Prepare for and practice interview questions from Revolve.

Revolve Interview Questions

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Select the 2nd highest salary in the engineering department

2nd Highest Salary

Write a SQL query to create a histogram of the number of comments per user in the month of January 2020.

Comments Histogram

Write a query that returns all neighborhoods that have 0 users.

Empty Neighborhoods

Write a query to return the two students with the closest test scores and the score difference

Closest SAT Scores

Write a query to return whether each user's subscription date range overlaps with any other completed subscription

Subscription Overlap

Data Structures & Algorithms

Given two sorted lists, write a function to merge them into one sorted list.

Merge Sorted Lists

Write a function n_frequent_words that returns the top N frequent words and their frequencies, and state its run-time

Get Top N Frequent Words

Write a function to group timestamps into 7-day lists starting from the first timestamp

Weekly Aggregation

Given an integer N, write a function that returns all of the prime numbers up to N

Prime to N

Given a string, write a function to find its first recurring character.

Recurring Character

Machine Learning

How would you encode a categorical variable with thousands of distinct values

Encoding Categorical Features

Interpret coefficients of logistic regression for categorical and boolean variables

Coefficients of Logistic Regression

Which model would perform better and why?

Booking Regression

Write a function calculate_rmse to calculate the root mean squared error from y_pred and y_true

RMS Error

How do we deal with the missing square footage data to construct our model

Missing Housing Data

A/B Testing

How would you assess the validity of the result?

Experiment Validity

How do we go about selecting the best 10,000 customers for the pre-launch?

Pre-Launching Shows

Button AB Test

A/B Test Power Size

How would you make a control group and test group to account for network effects

Network Experiment Design

Data Modeling

Design a data warehouse for a new online retailer

Retailer Data Warehouse

Create a schema to keep track of customer address changes

Address Schema

Design a database schema for a Tinder-style dating app and discuss needed optimizations

Swiping App Design

Design a cost-conscious analytics solution to store and query daily Kafka clickstream data with two-year retention

Clickstream Data

System design for a digital classroom service.

Digital Classroom System Design

<p>Write a SQL query to select the 2nd highest salary in the engineering department.</p>

<p><strong>Note:</strong> If more than one person shares the highest salary, the query should select the next highest salary.</p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>employees</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>first_name</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>last_name</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>salary</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>department_id</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
<p><code>departments</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>name</code></td>
<td>VARCHAR</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>salary</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>


<p>We’re given two tables, a <code>users</code> table with demographic information and the neighborhood they live in and a <code>neighborhoods</code> table.</p>

<p>Write a query that returns all neighborhoods that have 0 users. </p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>users</code> table</p>

<table>
<thead>
<tr>
<th>Columns</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>name</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>neighborhood_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>created_at</code></td>
<td>DATETIME</td>
</tr>
</tbody>
</table>
<p><code>neighborhoods</code> table</p>

<table>
<thead>
<tr>
<th>Columns</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>name</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>city_id</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>Columns</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>name</code></td>
<td>VARCHAR</td>
</tr>
</tbody>
</table>


<p>We’re given a table of bank transactions with three columns, <code>user_id</code>, a deposit or withdrawal value (determined if the value is positive or negative), and <code>created_at</code> time for each transaction.</p>

<p>Write a query to get the total three-day rolling average for deposits by day.</p>

<p><em>Note: Please use the format <code>&#39;%Y-%m-%d&#39;</code> for the date in the outout</em></p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>bank_transactions</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>user_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>created_at</code></td>
<td>DATETIME</td>
</tr>

<tr>
<td><code>transaction_value</code></td>
<td>FLOAT</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>dt</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>rolling_three_day</code></td>
<td>FLOAT</td>
</tr>
</tbody>
</table>


Write a query to get the total three-day rolling average for deposits by day

Rolling Bank Transactions

<p>Write a query to identify customers who placed more than three transactions each in both 2019 and 2020.</p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>transactions</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>user_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>created_at</code></td>
<td>DATETIME</td>
</tr>

<tr>
<td><code>product_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>quantity</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
<p><code>users</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>name</code></td>
<td>VARCHAR</td>
</tr>
</tbody>
</table>
<p> 
<strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>customer_name</code></td>
<td>VARCHAR</td>
</tr>
</tbody>
</table>


<p>Which of the following queries will return a list of customers and the total amount they have spent on orders?</p>


Which of the following queries will return a list of customers and the total amount they have spent on orders?

Customer Orders

Write a query to identify customers who placed more than three transactions each in both 2019 and 2020

<p>Write a SQL query to create a histogram of the number of comments per user in the month of January 2020.</p>

<p><em>Note: Assume bin buckets class intervals of one.</em></p>

<p><em>Note: Comments that were created outside of January 2020 should be counted in a “0” bucket</em></p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>users</code> table</p>

<table>
<thead>
<tr>
<th>Columns</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>name</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>created_at</code></td>
<td>DATETIME</td>
</tr>

<tr>
<td><code>neighborhood_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>mail</code></td>
<td>VARCHAR</td>
</tr>
</tbody>
</table>
<p><code>comments</code> table</p>

<table>
<thead>
<tr>
<th>Columns</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>user_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>body</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>created_at</code></td>
<td>DATETIME</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>comment_count</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>frequency</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>


<p>Given a table of students and their SAT test scores, write a query to return the two students with the closest test scores with the score difference.</p>

<p>If there are multiple students with the same minimum score difference, select the student name combination that is higher in the alphabet. </p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>scores</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>student</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>score</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>one_student</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>other_student</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>score_diff</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>


<p>Given a table of product subscriptions with a subscription start date and end date for each user, write a query that returns true or false whether or not each user has a subscription date range that overlaps with any other completed subscription.</p>

<p>Completed subscriptions have <code>end_date</code> recorded.</p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>subscriptions</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>user_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>start_date</code></td>
<td>DATETIME</td>
</tr>

<tr>
<td><code>end_date</code></td>
<td>DATETIME</td>
</tr>
</tbody>
</table>

<table>
<thead>
<tr>
<th><code>user_id</code></th>
<th><code>start_date</code></th>
<th><code>end_date</code></th>
</tr>
</thead>

<tbody>
<tr>
<td>1</td>
<td>2019-01-01</td>
<td>2019-01-31</td>
</tr>

<tr>
<td>2</td>
<td>2019-01-15</td>
<td>2019-01-17</td>
</tr>

<tr>
<td>3</td>
<td>2019-01-29</td>
<td>2019-02-04</td>
</tr>

<tr>
<td>4</td>
<td>2019-02-05</td>
<td>2019-02-10</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th><code>user_id</code></th>
<th><code>overlap</code></th>
</tr>
</thead>

<tbody>
<tr>
<td>1</td>
<td>1</td>
</tr>

<tr>
<td>2</td>
<td>1</td>
</tr>

<tr>
<td>3</td>
<td>1</td>
</tr>

<tr>
<td>4</td>
<td>0</td>
</tr>
</tbody>
</table>


<p>Given the <code>employees</code> and <code>departments</code> table, write a query to get the top 3 highest employee salaries by department. If the department contains less that 3 employees, the top 2 or the top 1 highest salaries should be listed (assume that each department has at least 1 employee). </p>

<p><em>Note: The output should include the full name of the employee in one column, the department name, and the salary. The output should be sorted by department name in ascending order and salary in descending order.</em> </p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>employees</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>first_name</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>last_name</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>salary</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>department_id</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
<p><code>departments</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>name</code></td>
<td>VARCHAR</td>
</tr>
</tbody>
</table>
<p><strong>Output</strong>:</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>employee_nam</code>e</td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>department_name</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>salary</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>


Get the top 3 highest employee salaries by department

Top Three Salaries

<p>We’re given a table of product purchases. Each row in the table represents an individual user product purchase.</p>

<p>Write a query to get the number of customers that were upsold, or in other words, the number of users who bought additional products after their first purchase.</p>

<p><em>Note: If the customer purchased two things on the same day, that does not count as an upsell, as they were purchased within a similar timeframe.</em></p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>transactions</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>user_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>created_at</code></td>
<td>DATETIME</td>
</tr>

<tr>
<td><code>product_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>quantity</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>num_of_upsold_customers</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>


Write a query to get the number of customers that were upsold

Upsell Transactions

<p>Write a query to show the number of users, number of transactions placed, and total order amount per month in the year 2020. Assume that we are only interested in the monthly reports for a single year (January-December).</p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>transactions</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>user_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>created_at</code></td>
<td>DATETIME</td>
</tr>

<tr>
<td><code>product_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>quantity</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
<p><code>products</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>name</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>price</code></td>
<td>FLOAT</td>
</tr>
</tbody>
</table>
<p><code>users</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>name</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>sex</code></td>
<td>VARCHAR</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>month</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>num_customers</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>num_orders</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>order_amt</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>


Write a query to show the number of users, transactions, and total order amount per month in 2020

Monthly Customer Report

<p>Given two sorted lists, write a function to merge them into one sorted list.</p>

<p><em>Bonus: What’s the time complexity?</em></p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<pre tabindex="0" class="chroma"><code><span class="line"><span class="cl"><span class="n">list1</span> <span class="o">=</span> <span class="p">[</span><span class="mi">1</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">5</span><span class="p">]</span>
</span></span><span class="line"><span class="cl"><span class="n">list2</span> <span class="o">=</span> <span class="p">[</span><span class="mi">2</span><span class="p">,</span><span class="mi">4</span><span class="p">,</span><span class="mi">6</span><span class="p">]</span>
</span></span></code></pre>

<p><strong>Output:</strong></p>

<pre tabindex="0" class="chroma"><code><span class="line"><span class="cl"><span class="k">def</span> <span class="nf">merge_list</span><span class="p">(</span><span class="n">list1</span><span class="p">,</span><span class="n">list2</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="p">[</span><span class="mi">1</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">4</span><span class="p">,</span><span class="mi">5</span><span class="p">,</span><span class="mi">6</span><span class="p">]</span>
</span></span></code></pre>


<p>You have two sorted lists, one with m elements and one with n elements. What would be the time complexity of merging the two lists via merge sort?</p>


You have two sorted lists, one with m elements and one with n elements. What would be the time complexity of merging the two lists via merge sort? 

Merging Lists Complexity

<p>How would you explain what a p-value is to someone who is not technical?</p>


<p>What does a p-value in a statistical test represent?</p>

What does a p-value in a statistical test represent?

P-value to a Layman I

<p>In a statistical test, how does a low p-value (less than 0.05) influence our decision about the null hypothesis?</p>

In a statistical test, how does a low p-value (less than 0.05) influence our decision about the null hypothesis?

P-value to a Layman II

Explain what a p-value is to someone who is not technical

P-value to a Layman

Statistics

<p>Write a function <code>compute_deviation</code> that takes in a list of dictionaries with a key and list of integers and returns a dictionary with the standard deviation of each list.</p>

<p><em>Note: This should be done without using the NumPy built-in functions.</em></p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<pre tabindex="0" class="chroma"><code><span class="line"><span class="cl"><span class="nb">input</span> <span class="o">=</span> <span class="p">[</span>
</span></span><span class="line"><span class="cl">    <span class="p">{</span>
</span></span><span class="line"><span class="cl">        <span class="s1">&#39;key&#39;</span><span class="p">:</span> <span class="s1">&#39;list1&#39;</span><span class="p">,</span>
</span></span><span class="line"><span class="cl">        <span class="s1">&#39;values&#39;</span><span class="p">:</span> <span class="p">[</span><span class="mi">4</span><span class="p">,</span><span class="mi">5</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">3</span><span class="p">,</span><span class="mi">4</span><span class="p">,</span><span class="mi">5</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">3</span><span class="p">],</span>
</span></span><span class="line"><span class="cl">    <span class="p">},</span>
</span></span><span class="line"><span class="cl">    <span class="p">{</span>
</span></span><span class="line"><span class="cl">        <span class="s1">&#39;key&#39;</span><span class="p">:</span> <span class="s1">&#39;list2&#39;</span><span class="p">,</span>
</span></span><span class="line"><span class="cl">        <span class="s1">&#39;values&#39;</span><span class="p">:</span> <span class="p">[</span><span class="mi">1</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">34</span><span class="p">,</span><span class="mi">12</span><span class="p">,</span><span class="mi">40</span><span class="p">,</span><span class="mi">3</span><span class="p">,</span><span class="mi">9</span><span class="p">,</span><span class="mi">7</span><span class="p">],</span>
</span></span><span class="line"><span class="cl">    <span class="p">}</span>
</span></span><span class="line"><span class="cl"><span class="p">]</span>
</span></span></code></pre>

<p><strong>Output:</strong></p>

<pre tabindex="0" class="chroma"><code><span class="line"><span class="cl"> <span class="n">output</span> <span class="o">=</span> <span class="p">{</span><span class="s1">&#39;list1&#39;</span><span class="p">:</span> <span class="mf">1.12</span><span class="p">,</span> <span class="s1">&#39;list2&#39;</span><span class="p">:</span> <span class="mf">14.19</span><span class="p">}</span>
</span></span></code></pre>


Write a function compute_deviation that returns the standard deviation of each list in a list of dictionaries

Compute Deviation

<p>Let’s say that your company is running a standard control and variant AB test on a feature to increase conversion rates on the landing page. The PM checks the results and finds a .04 p-value.</p>

<p>How would you assess the validity of the result?</p>


<p>Given two tables:  <code>accounts</code>, and <code>downloads</code>, find the average number of downloads for free vs paying accounts, broken down by day.</p>

<p><em>Note: You only need to consider accounts that have had at least one download before when calculating the average.</em></p>

<p><em>Note: round <code>average_downloads</code> to 2 decimal places.</em></p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>accounts</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>account_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>paying_customer</code></td>
<td>BOOLEAN</td>
</tr>
</tbody>
</table>
<p><code>downloads</code> table</p>

<table>
<thead>
<tr>
<th>column</th>
<th>type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>account_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>download_date</code></td>
<td>DATETIME</td>
</tr>

<tr>
<td><code>downloads</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>download_date</code></td>
<td>DATETIME</td>
</tr>

<tr>
<td><code>paying_customer</code></td>
<td>BOOLEAN</td>
</tr>

<tr>
<td><code>average_downloads</code></td>
<td>FLOAT</td>
</tr>
</tbody>
</table>


Write a query to find the average downloads for free vs paying accounts by day, rounded to 2 decimals

Download Facts

<p>Given a table of <code>transactions</code>, write a query to find the average quantity of each product purchased per transaction each year.</p>

<p>The output should include the year, product_id, and average quantity of the product purchased per transaction that year. The output table should be sorted by year and product_id in ascending order. The value for avg_quantity should be rounded to two decimal places.</p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong>
<code>transactions</code> table</p>

<table>
<thead>
<tr>
<th>Columns</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>user_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>created_at</code></td>
<td>DATETIME</td>
</tr>

<tr>
<td><code>product_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>quantity</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>Columns</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>year</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>product_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>avg_quantity</code></td>
<td>DECIMAL</td>
</tr>
</tbody>
</table>


Find the average yearly purchases for each product

Average Quantity

<p>Let’s say we have a table with an <code>id</code> and <code>name</code> fields. The table holds over 100 million rows and we want to sample a random row in the table without throttling the database.</p>

<p>Write a query to randomly sample a row from this table.</p>

<p><strong>Input:</strong></p>

<p><code>big_table</code> table</p>

<table>
<thead>
<tr>
<th>Columns</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>name</code></td>
<td>VARCHAR</td>
</tr>
</tbody>
</table>


Write a query to randomly sample a row from a big table.

Random SQL Sample

<p>Write a query to identify the manager with the biggest team size.</p>

<p>You may assume there is only one manager with the largest team size.</p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>employees</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>name</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>manager_id</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
<p><code>managers</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>name</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>team</code></td>
<td>VARCHAR</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>manager</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>team_size</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>


Manager Team Sizes

<p>Given a table of <code>transactions</code> and <code>products</code>, write a function to get the <code>month_over_month</code> change in revenue for the year 2019. Make sure to round <code>month_over_month</code> to 2 decimal places.</p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>transactions</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>user_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>created_at</code></td>
<td>DATETIME</td>
</tr>

<tr>
<td><code>product_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>quantity</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
<p><code>products</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>name</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>price</code></td>
<td>FLOAT</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>month</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>month_over_month</code></td>
<td>FLOAT</td>
</tr>
</tbody>
</table>


Write a function to get the month_over_month change in revenue for 2019 rounded to 2 decimal places

Month Over Month

<p>A team wants to A/B test multiple different changes through a sign-up funnel.</p>

<p>For example, on a page, a button is currently red and at the top of the page. They want to see if changing a button from red to blue and/or from the top of the page to the bottom of the page will increase click-through.</p>

<p>How would you set up this test?</p>


<p>Your team wants to run an AB test on the color (red or blue) and position (top/bottom of the page) of a button that links to a promotion.</p>

<p>How many different variants of the test should you run to see the effect that a red button has on the bottom of the page, if currently the button is blue and on the top of the page.</p>


Your team wants to run an AB test on the color (red or blue) and position (top/bottom of the page) of a button that links to a promotion.

How many different variants of the test should you run to see the effect that a red button has on the bottom of the page, if currently the button is blue and on the top of the page.

A/B Test Variants

<p>Write a query to create a new table, named flight routes, that displays unique pairs of two locations.</p>

<p><em>Note: Duplicate pairs from the <code>flights</code> table, such as Dallas to Seattle and Seattle to Dallas, should have one entry in the flight routes table.</em></p>

<h3>Schema</h3>

<p><code>flights</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>source_location</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>destination_location</code></td>
<td>VARCHAR</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>destination_one</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>destination_two</code></td>
<td>VARCHAR</td>
</tr>
</tbody>
</table>

<h3>Example</h3>

<p><strong>Input:</strong></p>

<p><strong><code>flights</code> table</strong></p>

<table>
<thead>
<tr>
<th>id</th>
<th>source_location</th>
<th>destination_location</th>
</tr>
</thead>

<tbody>
<tr>
<td>1</td>
<td>Seattle, WA</td>
<td>Dallas, TX</td>
</tr>

<tr>
<td>2</td>
<td>Dallas, TX</td>
<td>Seattle, WA</td>
</tr>

<tr>
<td>3</td>
<td>Seattle, WA</td>
<td>San Francisco, CA</td>
</tr>

<tr>
<td>4</td>
<td>San Francisco, CA</td>
<td>Dallas, TX</td>
</tr>

<tr>
<td>5</td>
<td>San Francisco, CA</td>
<td>Portland, OR</td>
</tr>

<tr>
<td>6</td>
<td>Seattle, WA</td>
<td>Dallas, TX</td>
</tr>

<tr>
<td>7</td>
<td>Portland, OR</td>
<td>San Francisco, CA</td>
</tr>

<tr>
<td>8</td>
<td>San Francisco, CA</td>
<td>Los Angeles, CA</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>destination_one</th>
<th>destination_two</th>
</tr>
</thead>

<tbody>
<tr>
<td>Dallas, TX</td>
<td>Seattle, WA</td>
</tr>

<tr>
<td>Portland, OR</td>
<td>San Francisco, CA</td>
</tr>

<tr>
<td>San Francisco, CA</td>
<td>Seattle, WA</td>
</tr>

<tr>
<td>Dallas, TX</td>
<td>San Francisco, CA</td>
</tr>

<tr>
<td>Los Angeles, CA</td>
<td>San Francisco, CA</td>
</tr>
</tbody>
</table>


Flight Records

<p>Given an integer <code>N</code>, write a function that returns a list of all of the prime numbers up to <code>N</code>.</p>

<p><em>Note: Return an empty list there are no prime numbers less than or equal to <code>N</code>.</em></p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<pre tabindex="0" class="chroma"><code><span class="line"><span class="cl"><span class="n">N</span> <span class="o">=</span> <span class="mi">3</span>
</span></span></code></pre>

<p><strong>Output:</strong></p>

<pre tabindex="0" class="chroma"><code><span class="line"><span class="cl"><span class="k">def</span> <span class="nf">prime_numbers</span><span class="p">(</span><span class="n">N</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="p">[</span><span class="mi">2</span><span class="p">,</span><span class="mi">3</span><span class="p">]</span>
</span></span></code></pre>


<p>Let’s say we have two tables, <code>transactions</code> and <code>products</code>. Hypothetically the <code>transactions</code> table consists of over a billion rows of purchases bought by users.</p>

<p>We are trying to find paired products that are often purchased together by the same user, such as wine and bottle openers, chips and beer, etc..</p>

<p>Write a query to find the top five paired products and their names.</p>

<p><em>Notes:</em>
   <em>For the purposes of satisfying the test case, p2 should be the item that comes first in the alphabet.</em>
   <em>The <code>qty</code> column represents paired products count</em></p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>transactions</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>user_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>created_at</code></td>
<td>DATETIME</td>
</tr>

<tr>
<td><code>product_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>quantity</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
<p><code>products</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>name</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>price</code></td>
<td>FLOAT</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>p1</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>p2</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>qty</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>


Paired Products

<p>There are two tables. One table is called <code>swipes</code> that holds a row for every Tinder swipe and contains a boolean column that determines if the swipe was a right or left swipe called <code>is_right_swipe</code>. The second is a table named <code>variants</code> that determines which user has which variant of an AB test.</p>

<p>Write a SQL query to output the average number of right swipes for two different variants of a feed ranking algorithm by comparing users that have swiped 10, 50, and 100 swipes in a <code>feed_change</code> experiment.</p>

<p><em>Note: Users have to have swiped at least 10 times to be included in the subset of users to analyze the mean number of right swipes.</em></p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>variants</code> table</p>

<table>
<thead>
<tr>
<th>Columns</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>experiment</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>variant</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>user_id</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
<p><code>swipes</code> table</p>

<table>
<thead>
<tr>
<th>Columns</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>user_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>swiped_user_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>created_at</code></td>
<td>DATETIME</td>
</tr>

<tr>
<td><code>is_right_swipe</code></td>
<td>BOOLEAN</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>Columns</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>variant</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>mean_right_swipes</code></td>
<td>FLOAT</td>
</tr>

<tr>
<td><code>swipe_threshold</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>num_users</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>


Write a SQL query to find the average number of right swipes for different ranking algorithms.

Swipe Precision

<p>Let’s say you work at a file-hosting website. You have information on user’s daily downloads in the <code>download_facts</code> table</p>

<p>Use the window function <code>RANK</code> to display the top three users by downloads each day. Order your data by <code>date</code>, and then by <code>daily_rank</code></p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>download_facts</code> table</p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>user_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>date</code></td>
<td>DATE</td>
</tr>

<tr>
<td><code>downloads</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th>Column</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>daily_rank</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>user_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>date</code></td>
<td>DATE</td>
</tr>

<tr>
<td><code>downloads</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>


Write a query to display the top three users by downloads each day

Top 3 Users

<p>Given a sorted list of positive integers with some entries being <code>None</code>, write a function to return a new list where all <code>None</code> values are replaced with the most recent non-<code>None</code> value in the list.</p>

<p><em>Note: If the first entry in the list is <code>None</code>, assume the previous entry was <code>0</code>.</em></p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<pre tabindex="0" class="chroma"><code><span class="line"><span class="cl"><span class="n">input_list</span> <span class="o">=</span> <span class="p">[</span><span class="mi">1</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="kc">None</span><span class="p">,</span><span class="kc">None</span><span class="p">,</span><span class="mi">4</span><span class="p">,</span><span class="mi">5</span><span class="p">,</span><span class="kc">None</span><span class="p">]</span>
</span></span></code></pre>

<p><strong>Output:</strong></p>

<pre tabindex="0" class="chroma"><code><span class="line"><span class="cl"><span class="k">def</span> <span class="nf">fill_none</span><span class="p">(</span><span class="n">input_list</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="p">[</span><span class="mi">1</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">4</span><span class="p">,</span><span class="mi">5</span><span class="p">,</span><span class="mi">5</span><span class="p">]</span> 
</span></span></code></pre>


Write a function to return a new list where all empty values are replaced with the most recent non-empty value in the list.

Fill None Values

<p>Given a table with event logs, find the top five users with the longest continuous streak of visiting the platform.</p>

<p><em>Note: A continuous streak counts if the user visits the platform at least once per day on consecutive days.</em></p>

<p><strong>Example:</strong></p>

<p><strong>Input:</strong></p>

<p><code>events</code> table</p>

<table>
<thead>
<tr>
<th><code>Column</code></th>
<th><code>Type</code></th>
</tr>
</thead>

<tbody>
<tr>
<td><code>user_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>created_at</code></td>
<td>DATETIME</td>
</tr>

<tr>
<td><code>url</code></td>
<td>VARCHAR</td>
</tr>
</tbody>
</table>
<p><strong>Output:</strong></p>

<table>
<thead>
<tr>
<th><code>Column</code></th>
<th><code>Type</code></th>
</tr>
</thead>

<tbody>
<tr>
<td><code>user_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>streak_length</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>


Longest Streak Users

<p>Given a string, write a function <code>recurring_char</code> to find its first recurring character. Return <code>None</code> if there is no recurring character.</p>

<p>Treat upper and lower case letters as distinct characters.</p>

<p>You may assume the input string includes no spaces.</p>

<p><strong>Example 1:</strong></p>

<p><strong>Input:</strong></p>

<pre tabindex="0" class="chroma"><code><span class="line"><span class="cl"><span class="nb">input</span> <span class="o">=</span> <span class="s2">&#34;interviewquery&#34;</span>
</span></span></code></pre>

<p><strong>Output:</strong></p>

<pre tabindex="0" class="chroma"><code><span class="line"><span class="cl"><span class="n">output</span> <span class="o">=</span> <span class="s2">&#34;i&#34;</span>
</span></span></code></pre>

<p><strong>Example 2:</strong></p>

<p><strong>Input:</strong></p>

<pre tabindex="0" class="chroma"><code><span class="line"><span class="cl"><span class="nb">input</span> <span class="o">=</span> <span class="s2">&#34;interv&#34;</span>
</span></span></code></pre>

<p><strong>Output:</strong></p>

<pre tabindex="0" class="chroma"><code><span class="line"><span class="cl"><span class="n">output</span> <span class="o">=</span> <span class="kc">None</span>
</span></span></code></pre>


<p>Let’s say that you work at a bank that wants to build a model to detect fraud on the platform.</p>

<p>The bank wants to implement a text messaging service in addition that will text customers when the model detects a fraudulent transaction in order for the customer to approve or deny the transaction with a text response.</p>

<p>How would we build this model?</p>


<p>Let’s say that you work at a bank that wants to build a model to detect fraud on the platform.</p>

<p>The bank wants to implement a text messaging service that will text customers when the model detects a fraudulent transaction in order for the customer to approve or deny the transaction with a text response.</p>

<p>Which statement is true?</p>


Let's say that you work at a bank that wants to build a model to detect fraud on the platform.

The bank wants to implement a text messaging service that will text customers when the model detects a fraudulent transaction in order for the customer to approve or deny the transaction with a text response.

Which statement is true?

Bank Fraud Model

How would we build a model to detect fraud and text customers to approve or deny fraudulent transactions

<p>A jar holds 1000 coins. Out of all of the coins, 999 are fair and one is double-sided with two heads. Picking a coin at random, you toss the coin ten times.</p>

<p>Given that you see 10 heads, what is the probability that the coin is double headed and the probability that the next toss of the coin is also a head?</p>


Compute the probability the coin is double headed and the probability the next toss is a head given 10 heads

Jars and Coins

Probability

Challenge

<h3>Job Description</h3><div>Job Description<div><div><div><p><strong>Meet REVOLVE: </strong></p><p><em>REVOLVE is the next-generation fashion retailer for Millennial and Generation Z consumers. As </em><em>a trusted, premium lifestyle brand, and a go-to online source for discovery and inspiration, we </em><em>deliver an engaging customer experience from a vast yet curated offering totaling over 45,000 </em><em>apparel, footwear, accessories and beauty styles. Our dynamic platform connects a deeply </em><em>engaged community of millions of consumers, thousands of global fashion influencers, and </em><em>more than 500 emerging, established and owned brands. Through 16 years of continued </em><em>investment in technology, data analytics, and innovative marketing and merchandising </em><em>strategies, we have built a powerful platform and brand that we believe is connecting with the </em><em>next generation of consumers and is redefining fashion retail for the 21st century. For more </em><em>information please visit www.revolve.com.<br /></em></p><p><em>At REVOLVE the most successful team members have a thirst and the creativity to make this </em><em>the top e-commerce brand in the world. With a team of 1,000+ based out of Cerritos, California </em><em>we are a dynamic bunch that are motivated by getting the company to the next level. It’s our </em><em>goal to hire high-energy, diverse, bright, creative, and flexible individuals who thrive in a fast-</em><em>paced work environment. </em></p><p><em>Some of the sweetest perks we offer aren’t in a typical benefit package like hefty discount on </em><em>items we carry – as in 50% or more off retail prices, free weekly lunches, and pretty rad </em><em>company parties.<br /></em></p><p><em>To take a behind the scenes look at the REVOLVE “corporate” lifestyle check out our Instagram </em><em>@REVOLVEcareers or #lifeatrevolve.</em></p><p><strong>Are you ready to set the standard for Premium apparel?</strong></p><p><strong> </strong></p><p><strong>Main purpose of the Brand Marketing Analyst role:</strong></p><p>Lead insights generation and performance measurement across brand marketing initiatives. Serve as a key liaison between marketing, analytics, and executive stakeholders, driving optimization through data storytelling, robust experimentation, and cross-channel analysis.</p><p><strong>Major Responsibilities:</strong></p><p>Essential Duties and Responsibilities include the following. Other duties may be assigned.</p><ul><li>Outstanding analytical skills, with strong academic background in Marketing Analytics, Economics, Business, or a related field.</li><li>Proficiency in SQL and data visualization tools (e.g., Tableau, Looker); familiarity with statistical testing and modeling tools (e.g., Python, R) is a plus.</li><li>Proven business acumen and results oriented mindset.</li><li>Excellent communication and stakeholder management skills.</li><li>Proven experience translating complex data into strategic insights that influence executive decision-making.</li></ul><p><strong>Minimum Qualifications:</strong></p><ul><li>A BA/BS Degree is required</li><li>3+ years of experience in a strong analytical environment</li><li>Proficiency in Tableau and Excel</li><li>SQL and database knowledge</li><li>Strong written and verbal communication</li></ul><p><strong>Preferred Qualifications:</strong></p><ul><li>Background in brand lift studies (e.g., Meta, YouTube, or survey-based)</li><li>Working knowledge of media mix modeling (MMM) or multi-touch attribution (MTA) frameworks.</li><li>Industry experience in consumer-facing brands, such as fashion & beauty</li><li>Statistical background</li><li>Experience in omnichannel marketing environments, including paid media, influencer, PR, content, and organic social.</li><li>Experience with coaching and mentorship for others</li></ul><p><br /></p><p>A successful candidate works well in a dynamic environment with minimal supervision. At REVOLVE we all roll up our sleeves to pitch-in and do whatever it takes to get the job done. Each day is a little different, it’s what keeps us on our toes and excited to come to work every day. </p><p><br /></p><p><br /></p><p>For individuals assigned and/or hired to work in California, Revolve includes a reasonable estimate of the salary or hourly rate range for this role. This takes into account the wide range of factors that are considered in making compensation decisions; including but not limited to business or organizational needs, skill sets, experience and training, licensure, and certifications.</p><p><br /></p><p>A reasonable estimate of the current base salary range is $75,000 to $90,000.</p><p><br /></p><p><strong>ATTENTION:</strong></p><p>After submitting your application, please check your spam folder for emails on your application status. Emails are sent from an ADP email address.</p><p><br /></p></div></div></div></div>

<h3>Job Description</h3><div>Job Description<div><div><div><div><div><div></div></div></div></div></div><div><p><strong>Meet REVOLVE: </strong></p><p><em>REVOLVE is the next-generation fashion retailer for Millennial and Generation Z consumers. As a trusted, premium lifestyle brand, and a go-to online source for discovery and inspiration, we deliver an engaging customer experience from a vast yet curated offering totaling over 45,000 apparel, footwear, accessories and beauty styles. Our dynamic platform connects a deeply engaged community of millions of consumers, thousands of global fashion influencers, and more than 500 emerging, established and owned brands. Through 20 years of continued investment in technology, data analytics, and innovative marketing and merchandising strategies, we have built a powerful platform and brand that we believe is connecting with the next generation of consumers and is redefining fashion retail for the 21st century. For more information please visit www.revolve.com.</em></p><p>At REVOLVE the most successful team members have the thirst and creativity to redefine fashion retail for the 21st century, making REVOLVE the leading online retail destination targeted towards Millennial and Generation Z consumers seeking premium fashion. With a team of 1,000 strong, we are a dynamic bunch that are motivated by getting the company to the next level. It’s our goal to hire high-energy, diverse, bright, creative, and flexible individuals who thrive in a fast-paced work environment. </p><p>Some of the sweetest perks we offer aren’t in a typical benefit package like hefty discount on items we carry – as in 50% or more off retail prices, free weekly lunches, and pretty rad company parties. </p><p>To take a behind the scenes look at the REVOLVE “corporate” lifestyle check out our Instagram @REVOLVEcareers or #lifeatrevolve.</p><p>Are you ready to set the standard for Premium apparel?</p><p><br /></p><p><strong>Main purpose of the Software Engineer role:</strong></p><p>This is a full-time role for a candidate who will develop and maintain software services and reporting software used by Finance and Planning teams.</p><p><br /></p><p><strong>Major Responsibilities:</strong></p><p>Essential Duties and Responsibilities include the following. Other duties may be assigned.</p><p>• Analyze user requirement and develop new modules for external customers and internal business processes.</p><p>• Implement, maintain and troubleshoot database driven internal applications using SQL, Java, JSP, Spring MVC, Javascript and Redis.</p><p>• Troubleshoot issues, perform analyses and provide efficient solutions for operations, warehouse and international marketing teams.</p><p><br /></p><p><strong>Required Competencies:</strong></p><p>To perform the job successfully, an individual should demonstrate the following competencies:</p><p>• Develop and deploy bug free code to production on a daily basis</p><p>• Communicate effectively with internal end users (Business Owners) and working with them to refine specs for tasks.</p><p>• Must be comfortable coding applications from start to finish on a fast pace.</p><p><br /></p><p><strong>Minimum Qualifications:</strong></p><p>• 4-5 Years of professional work experience</p><p>• Bachelors in Computer Science/Computer Engineering or equivalent degree</p><p>• Java, SQL, Redis, Java Spring Framework, Javascript</p><p><br /></p><p><strong>Preferred Qualifications: </strong></p><p>• Bachelors or Masters Degree in Computer Science/Computer Engineering</p><p>• Java, Sql, Redis, Java Spring Framework, Webpack, Javascript</p><p><br /></p><p>A successful candidate works well in a dynamic environment with minimal supervision. At REVOLVE we all roll up our sleeves to pitch-in and do whatever it takes to get the job done. Each day is a little different, it’s what keeps us on our toes and excited to come to work every day. </p><p><br /></p><p>For individuals assigned and/or hired to work in California, Revolve includes a reasonable estimate of the salary or hourly rate range for this role. This takes into account the wide range of factors that are considered in making compensation decisions; including but not limited to business or organizational needs, skill sets, experience and training, licensure, and certifications.</p><p>A reasonable estimate of the current base salary range is $110,000 /year - $130,000 /year</p><p><br /></p><p><strong>ATTENTION:</strong></p><p>After submitting your application, please check your spam folder for emails on your application status. Emails are sent from an ADP email address.</p><p>The following job description contains representative examples of work that will be performed in positions allocated to this classification. It is not required that any position perform all of the duties listed, so long as primary responsibilities are consistent with the work as described. Roles and responsibilities can often be expanded to accommodate changing business conditions and goals, as well as to tap into the skills and talents of the individuals in the company. Accordingly, associates may be asked to perform duties that are outside the specific functions that are listed.</p></div></div></div>

<h3>Job Description</h3><div>Job Description<div><div><div><div><p><br /></p><p><strong>Meet REVOLVE: </strong></p><p><em>REVOLVE is the next-generation fashion retailer for Millennial and Generation Z consumers. As </em><em>a trusted, premium lifestyle brand, and a go-to online source for discovery and inspiration, we </em><em>deliver an engaging customer experience from a vast yet curated offering totaling over 45,000 </em><em>apparel, footwear, accessories and beauty styles. Our dynamic platform connects a deeply </em><em>engaged community of millions of consumers, thousands of global fashion influencers, and </em><em>more than 500 emerging, established and owned brands. Through 16 years of continued </em><em>investment in technology, data analytics, and innovative marketing and merchandising </em><em>strategies, we have built a powerful platform and brand that we believe is connecting with the </em><em>next generation of consumers and is redefining fashion retail for the 21st century. For more </em><em>information please visit www.revolve.com.</em><br /><em><br /></em></p><p><em>At REVOLVE the most successful team members have a thirst and the creativity to make this </em><em>the top e-commerce brand in the world. With a team of 1,000+ based out of Cerritos, California </em><em>we are a dynamic bunch that are motivated by getting the company to the next level. It’s our </em><em>goal to hire high-energy, diverse, bright, creative, and flexible individuals who thrive in a fast-</em><em>paced work environment. </em></p><p><em> </em></p><p><em>Some of the sweetest perks we offer aren’t in a typical benefit package like hefty discount on </em><em>items we carry – as in 50% or more off retail prices, free weekly lunches, and pretty rad </em><em>company parties.</em><br /><em><br /></em></p><p><em>To take a behind the scenes look at the REVOLVE “corporate” lifestyle check out our Instagram </em><em>@REVOLVEcareers or #lifeatrevolve.</em><br><br></p><p><strong>Are you ready to set the standard for Premium apparel?</strong></p><p><strong> </strong></p><p><strong>Main purpose of the Data Analyst, Editorial & Merchandising Strategy role:</strong><br><br></p><p>We’re looking for a highly analytical, detail-oriented Data Analyst to join the Merchandising team. Unlike traditional BI roles, this position is embedded within the merchandising organization and focused on connecting performance data to our brand storytelling and fashion positioning. Reporting into the Director of Editorial & Merchandising Strategy, you’ll be responsible for aggregating data across channels, analyzing performance through a merchandising and content lens, and delivering clear, actionable insights that help the team make adjustments in real time. Your work will directly inform how we position product, link stories, optimize imagery, refine copy, and ultimately drive traffic and conversion.<br><br></p><p><strong>Major Responsibilities:</strong></p><p>Essential Duties and Responsibilities include the following. Other duties may be assigned.</p><div><ul><li>Aggregate and synthesize data from multiple sources (email, site, social, paid, merchandising reports) into a cohesive weekly performance readout. </li><li>Translate data into insights tied to editorial and merchandising strategy, highlighting what’s working and what’s not in areas such as imagery, copy, linking strategy, and product performance.</li><li>Present weekly findings in a clear, digestible format to merchandising and marketing leadership, enabling quick pivots and real-time adjustments.</li><li>Own recurring reporting (weekly, monthly, quarterly) across product categories, campaigns, and trend shops — connecting results back to topline brand and merchandising strategies.</li><li>Identify shifts in customer behavior, content engagement, and merchandising opportunities, surfacing recommendations proactively.</li><li>Build dashboards and reports using BI tools (ie Tableau or similar) to track KPIs such as sell-through, conversion, AOV, click-through, and engagement.</li><li>Partner with BI/data teams to ensure accuracy and consistency of data, while tailoring insights specifically to merchandising and content needs.</li><li>Act as the “data translator” within the merchandising team, ensuring analytics are always framed within the context of storytelling</li></ul></div><p></p><p><strong>Required Competencies:</strong></p><p>To perform the job successfully, an individual should demonstrate the following competencies:</p><div><ul><li>2–4 years of experience in an analytical role (ideally within retail, e-commerce, or consumer-facing industry). </li><li>Advanced Excel and SQL skills; experience with BI/visualization tools (Tableau, Looker, PowerBI, or Domo). </li><li>Strong business acumen with the ability to connect data directly to marketing, merchandising, and content strategies.</li><li>Skilled at synthesizing complex data into concise, actionable takeaways that non-technical partners can use immediately.</li><li>Detail-oriented, proactive, and comfortable working independently in a fast-paced environment. </li><li>Excellent communication and presentation skills, with a talent for framing insights within a broader narrative.</li><li> A collaborative team player who understands the strategic vision of editorial and merchandising, not just the numbers</li></ul></div><p><br /></p><p></p><p>A successful candidate works well in a dynamic environment with minimal supervision. At REVOLVE we all roll up our sleeves to pitch-in and do whatever it takes to get the job done. Each day is a little different, it’s what keeps us on our toes and excited to come to work every day. </p><p></p><p></p><p>For individuals assigned and/or hired to work in California, Revolve includes a reasonable estimate of the salary or hourly rate range for this role. This takes into account the wide range of factors that are considered in making compensation decisions; including but not limited to business or organizational needs, skill sets, experience and training, licensure, and certifications.</p><p></p><p>A reasonable estimate of the current base hourly/salary range is $100,000 to $110,000.</p><p></p><p></p><p></p><p><strong>ATTENTION:</strong></p><p>After submitting your application, please check your spam folder for emails on your application status. Emails are sent from an ADP email address.</p><p></p><p><br /></p></div></div></div></div></div>

<h3>Job Description</h3><div>Job Description<div><div><div><div></div></div></div><div><div></div></div><div><p><strong>Meet REVOLVE:</strong></p><p>REVOLVE is the next-generation fashion retailer for Millennial and Generation Z consumers. As a trusted, premium lifestyle brand, and a go-to online source for discovery and inspiration, we deliver an engaging customer experience from a vast yet curated offering totaling over 45,000 apparel, footwear, accessories and beauty styles. Our dynamic platform connects a deeply engaged community of millions of consumers, thousands of global fashion influencers, and more than 500 emerging, established and owned brands. Through 16 years of continued investment in technology, data analytics, and innovative marketing and merchandising strategies, we have built a powerful platform and brand that we believe is connecting with the next generation of consumers and is redefining fashion retail for the 21st century. For more information please visit www.revolve.com.</p><p>At REVOLVE the most successful team members have a thirst and the creativity to make this the top e-commerce brand in the world. With a team of 1,000+ based out of Cerritos, California we are a dynamic bunch that are motivated by getting the company to the next level. It’s our goal to hire high-energy, diverse, bright, creative, and flexible individuals who thrive in a fast-paced work environment. In return, we promise to keep REVOLVE a company where inspired people will always thrive. </p><p>To take a behind the scenes look at the REVOLVE “corporate” lifestyle check out our Instagram @REVOLVEcareers or #lifeatrevolve.</p><p><strong>Are you ready to set the standard for Premium apparel?</strong></p><p>Main purpose of the Data Science Analyst role:</p><p>Use a diverse skill sets across math and computer science, dedicated to solving complex and analytically challenging problems here at Revolve.</p><p><strong>Major Responsibilities:</strong></p><p>Essential Duties and Responsibilities include the following. Other duties may be assigned.</p><ul><li>Partner closely with business leaders in Marketing, Product, Operations, Buying team to plan out valuable data science projects</li><li>Conduct complex analysis and build models to uncover key learning form data, leading to appropriate strategy recommendations.</li><li>Work closely with the DBA to improve BI’s infrastructure, architect the reporting system, and invest in time for technical proof of concept. </li><li>Work closely with the business intelligence and tech team to define, automate and validate the extraction of new metrics from various data sources for use in future analysis</li><li>Work alongside business stakeholders to apply our findings and models in website personalization, product recommendations, marketing optimization, to fraud detection, demand forecast, CLV prediction.</li></ul><p><strong>Required Competencies:</strong></p><p>To perform the job successfully, an individual should demonstrate the following competencies:</p><ul><li>Outstanding analytical skills, with strong academic background in statistics, math, science or technology.</li><li>High comfort level with programming, ability to learn and adopt new technology with short turn-around time.</li><li>Knowledge of quantitative methods in statistics and machine learning </li><li>Intense intellectual curiosity – strong desire to always be learning</li><li>Proven business acumen and results oriented.</li><li>Ability to demonstrate logical thinking and problem solving skills</li><li>Strong attention to detail</li></ul><p><strong>Minimum Qualifications:</strong></p><ul><li>Master Degree is required</li><li>3+ years of DS and ML experience in a strong analytical environment.</li><li>Proficient in Python, NumPy and other packages</li><li>Familiar with statistical and ML methodology: causal inference, logistic regression, tree-based models, clustering, model validation and interpretations. </li><li>Experience with AB Testing and pseudo-A/B test setup and evaluations</li><li>Advanced SQL experience, query optimization, data extract</li><li>Ability to build, validate, and productionize models</li></ul><p><strong>Preferred Qualifications:</strong></p><ul><li>Strong business acumen</li><li>Experience in deploying end to end Machine Learning models</li><li>5+ years of DS and ML experience preferred</li><li>Advanced SQL and Python, with query and coding optimization experience</li><li>Experience with E-commerce marketing and product analytics is a plus<br><br></li></ul><p>A successful candidate works well in a dynamic environment with minimal supervision. At REVOLVE we all roll up our sleeves to pitch-in and do whatever it takes to get the job done. Each day is a little different, it’s what keeps us on our toes and excited to come to work every day. </p><p>A reasonable estimate of the current base salary range is $90,000 to $120,000 per year.</p><p><strong>ATTENTION:</strong></p><p>After submitting your application, please check your spam folder for emails on your application status. Emails are sent from an ADP email address.</p><p>The following job description contains representative examples of work that will be performed in positions allocated to this classification. It is not required that any position perform all of the duties listed, so long as primary responsibilities are consistent with the work as described. Roles and responsibilities can often be expanded to accommodate changing business conditions and goals, as well as to tap into the skills and talents of the individuals in the company. Accordingly, associates may be asked to perform duties that are outside the specific functions that are listed.</p><p><br /></p><p><br /></p></div></div></div>

<h3>Job Description</h3><div>Job Description<div><p><strong>Meet REVOLVE: </strong></p><p><em>REVOLVE is the next-generation fashion retailer for Millennial and Generation Z consumers. As </em><em>a trusted, premium lifestyle brand, and a go-to online source for discovery and inspiration, we </em><em>deliver an engaging customer experience from a vast yet curated offering totaling over 45,000 </em><em>apparel, footwear, accessories and beauty styles. Our dynamic platform connects a deeply </em><em>engaged community of millions of consumers, thousands of global fashion influencers, and </em><em>more than 500 emerging, established and owned brands. Through 16 years of continued </em><em>investment in technology, data analytics, and innovative marketing and merchandising </em><em>strategies, we have built a powerful platform and brand that we believe is connecting with the </em><em>next generation of consumers and is redefining fashion retail for the 21st century. For more </em><em>information please visit www.revolve.com.<br /></em></p><p><em>At REVOLVE the most successful team members have a thirst and the creativity to make this </em><em>the top e-commerce brand in the world. With a team of 1,000+ based out of Cerritos, California </em><em>we are a dynamic bunch that are motivated by getting the company to the next level. It’s our </em><em>goal to hire high-energy, diverse, bright, creative, and flexible individuals who thrive in a fast-</em><em>paced work environment. </em></p><p><em>Some of the sweetest perks we offer aren’t in a typical benefit package like hefty discount on </em><em>items we carry – as in 50% or more off retail prices, free weekly lunches, and pretty rad </em><em>company parties.<br /></em></p><p><em>To take a behind the scenes look at the REVOLVE “corporate” lifestyle check out our Instagram </em><em>@REVOLVEcareers or #lifeatrevolve.</em></p><p><strong>Are you ready to set the standard for Premium apparel?</strong></p><p><strong> </strong></p><p><strong>Main purpose of the Senior Data Scientist role:</strong></p><p>Use a diverse skill sets across math and computer science, dedicated to solving complex and analytically challenging problems here at Revolve. </p><p><strong>Major Responsibilities:</strong></p><p>Essential Duties and Responsibilities include the following. Other duties may be assigned.</p><ul><li>Partner closely with business leaders in Marketing, Product, Operations, Buying team to plan out valuable data science projects</li><li>Mentor junior data scientists and analysts, providing guidance on best practices and methodologies</li><li>Conduct complex analysis and build models to uncover key learning form data, leading to appropriate strategy recommendations.</li><li>Work closely with the DBA to improve BI’s infrastructure, architect the reporting system, and invest in time for technical proof of concept. </li><li>Work closely with the business intelligence and tech team to define, automate and validate the extraction of new metrics from various data sources for use in future analysis</li><li>Work alongside business stakeholders to apply our findings and models in website personalization, product recommendations, marketing optimization, to fraud detection, demand forecast, CLV prediction.</li><li>Experiment with new tools, technologies, and methodologies to enhance AI and Data Science capabilities. Contribute to the development of the company's data science strategy and roadmap</li></ul><p><strong>Required Competencies:</strong></p><p>To perform the job successfully, an individual should demonstrate the following competencies:</p><ul><li>Outstanding analytical skills, with strong academic background in statistics, math, science or technology.</li><li>High comfort level with programming, ability to learn and adopt new technology with short turn-around time.</li><li>Knowledge of quantitative methods in statistics and machine learning </li><li>Intense intellectual curiosity – strong desire to always be learning</li><li>Proven business acumen and results oriented.</li><li>Ability to demonstrate logical thinking and problem solving skills</li><li>Strong attention to detail</li></ul><p><strong>Minimum Qualifications:</strong></p><ul><li>Master Degree is required</li><li>3+ years of DS and ML experience in a strong analytical environment.</li><li>Proficient in Python, NumPy and other packages</li><li>Familiar with statistical and ML methodology: causal inference, logistic regression, tree-based models, clustering, model validation and interpretations. </li><li>Experience with AB Testing and pseudo-A/B test setup and evaluations</li><li>Advanced SQL experience, query optimization, data extract</li><li>Ability to build, validate, and productionize models</li></ul><p><strong>Preferred Qualifications:</strong></p><ul><li>Strong business acumen</li><li>Experience in deploying end to end Machine Learning models</li><li>5+ years of DS and ML experience preferred</li><li>Advanced SQL and Python, with query and coding optimization experience</li><li>Experience with E-commerce marketing and product analytics is a plus</li></ul><p></p><p>A successful candidate works well in a dynamic environment with minimal supervision. At REVOLVE we all roll up our sleeves to pitch-in and do whatever it takes to get the job done. Each day is a little different, it’s what keeps us on our toes and excited to come to work every day. </p><p></p><p></p><p>For individuals assigned and/or hired to work in California, Revolve includes a reasonable estimate of the salary or hourly rate range for this role. This takes into account the wide range of factors that are considered in making compensation decisions; including but not limited to business or organizational needs, skill sets, experience and training, licensure, and certifications.</p><p></p><p>A reasonable estimate of the current base hourly/salary range is $120,000 to $150,000/ year.</p><p></p><p></p><p></p><p><strong>ATTENTION:</strong></p><p>After submitting your application, please check your spam folder for emails on your application status. Emails are sent from an ADP email address.</p><p></p></div></div>

Calculate Moving Average	SQL	Easy
Predict Customer Churn	Machine Learning	Medium
A/B Test Significance	Statistics	Medium
Optimize Query Performance	SQL	Hard
Feature Importance Analysis	Machine Learning	Medium
Clean Missing Data	Python	Easy
Neural Network Architecture	Deep Learning	Hard
Calculate Cohort Retention	SQL	Medium
Bayesian Probability	Statistics	Easy
Recommend Similar Products	Machine Learning	Hard

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