Prepare for and practice interview questions from Step.

Step Interview Questions

Step Interview Guides

Data Structures & Algorithms

Given a list of integers, and an integer N, write a function to find all combinations that sum to the value N.

Sum to N

Write a function moving_window to find the moving window average

Moving Window

Write a function to parse the most frequent words.

Word Frequency

Write a function is_subsequence to find out if string1 is a subsequence of string2

String Subsequence

Write a function `sorting` from scratch to sort a list of strings in ascending alphabetical order

Sort Strings

Product Sense & Metrics

Google Maps Improvement

Let's say that we want to improve the "search" feature on the Facebook app.

Improve Search Results

What are the top five metrics you would start tracking to understand the health of Google Docs

Docs Metrics

The role of A/B testing in measuring the success rate of an analytics experiment

Success Measurement

Behavioral

Describing a data project and its challenges

Hurdles In Data Projects

How would you negotiate and resolve disagreements when a client rejects your proposed solution?

Client Solution Pushback

What do you tell an interviewer when they ask you what your strengths and weaknesses are?

Your Strengths and Weaknesses

Machine Learning

In which case would you use a bagging algorithm versus a boosting algorithm

Bagging vs Boosting

How would you justify the complexity of building such a model and explain the predictions to non-technical stakeholders

Justify a Neural Network

Mapping Nicknames

Write a query to get the percentage of search queries where all ratings are less than 3 rounded to two decimals

Search Ranking

Given a list of <code>integers</code>, and an integer <code>N</code>, write a function <code>sum_to_n</code> to find all combinations that sum to the value <code>N</code>.

Example: 

Input:

<pre tabindex="0" class="chroma"><code>integers = [2,3,5]
N = 8
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>def sum_to_n(integers, N) -&gt;
 [
 [2,2,2,2],
 [2,3,3],
 [3,5]
]
</code></pre>

Let’s say we’re comparing two machine learning algorithms. In which case would you use a bagging algorithm versus a boosting algorithm? 

Give an example of the tradeoffs between the two.

In machine learning, when would you use a bagging algorithm over a boosting algorithm?

In machine learning, when would you use a bagging algorithm over a boosting algorithm?

Bagging vs. Boosting

Given a string, find the first non-repeating character in it and return its index. If it doesn’t exist, return -1.

Example questions:

Consider a string where all characters are lowercase alphabets.

Example 1:

Input:

<pre tabindex="0" class="chroma"><code>s = &#39;helloworld&#39;
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>first_uniq_char(s) -&gt; 0
</code></pre>

In the string ‘helloworld’, the first non-repeating character is ‘h’, which is at index 0.

Example 2:

Input:

<pre tabindex="0" class="chroma"><code>s = &#39;concussion&#39;
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>first_uniq_char(s) -&gt; 4
</code></pre>

In the string ‘concussion’, the first non-repeating character is ‘u’, which is at index 4.

This problem involves finding the first non-repeating character in a given string. The solution involves iterating over the string and keeping track of the frequency of each character. The first character that has a frequency of 1 is the first non-repeating character.

Find the First Non-Repeating Character in a String

You’re given a table that represents search results from searches on Facebook. The <code>query</code> column is the search term, <code>position</code> column represents each position the search result came in, and the <code>rating</code> column represents the human rating of the result from 1 to 5 where 5 is high relevance and 1 is low relevance.

Write a query to get the percentage of search queries where all of the ratings for the query results are less than a rating of 3. Please round your answer to two decimal points.

Example:

Input:

<code>search_results</code> table

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

<tbody>
<tr>
<td><code>result_id</code></td>
<td>INTEGER (primary key)</td>
</tr>

<tr>
<td><code>query</code></td>
<td>TEXT</td>
</tr>

<tr>
<td><code>position</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>rating</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
Output:

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

<tbody>
<tr>
<td><code>percentage_less_than_3</code></td>
<td>FLOAT</td>
</tr>
</tbody>
</table>

Given two strings, <code>string1</code> and <code>string2</code>, write a function <code>is_subsequence</code> to find out if <code>string1</code> is a subsequence of <code>string2</code>.

Bonus: A subsequence is a sequence that can be derived from another sequence by deleting some elements without changing the order of the remaining elements.

Example:

Input:

<pre tabindex="0" class="chroma"><code>string1 = &#39;abc&#39;
string2 = &#39;asbsc&#39;
string3 = &#39;acedb&#39;

is_subsequence(string1, string2) -&gt; True
is_subsequence(string1, string3) -&gt; False
</code></pre>

Let’s say that you’re the PM on Google Maps.

<ol>
<li>How would you improve Google Maps?</li>

<li>What metrics would you check to see if your feature improvements are successful?</li>
</ol>

Given a list of strings, write a function, <code>sorting</code> from scratch to sort the list in ascending alphabetical order.

Notes:
- Do NOT use the built-in <code>sorted</code> function
- Return the new sorted list, rather than modifying the list in-place

Bonus: Have your solution be \(O(n log(n))\).

Example:

Input:

<pre tabindex="0" class="chroma"><code>array = [&#34;apple&#34;, &#34;cat&#34;, &#34;banana&#34;, &#34;zoo&#34;, &#34;football&#34;]
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>def sorting(array) -&gt; [&#34;apple&#34;, &#34;banana&#34;, &#34;cat&#34;, &#34;football&#34;, &#34;zoo&#34;]
</code></pre>

You are asked to implement a simple regex parser which supports two operations: <code>&#39;.&#39;</code> and <code>&#39;*&#39;</code>. The <code>&#39;.&#39;</code> operation matches any single character, while the <code>&#39;*&#39;</code> operation matches zero or more of the preceding element. The matching should cover the entire input string (not partial).

Write a function <code>isMatch(s,p)</code> which takes in two parameters, the string and the regex pattern. It should return a Boolean output indicating a ‘match success’ or a ‘match failure’.

Example 1:

Input:

<pre tabindex="0" class="chroma"><code>s = &#39;aa&#39;
p = &#39;a&#39;
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>isMatch(s, p) -&gt; False
</code></pre>

Explanation: ‘a’ does not match the entire string ‘aa’.

Example 2:

Input:

<pre tabindex="0" class="chroma"><code>s = &#39;aa&#39;
p = &#39;a*&#39;
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>isMatch(s, p) -&gt; True
</code></pre>

Explanation: ‘*’ means zero or more of the preceding element, ‘a’. Therefore, by repeating ‘a’ once, it becomes ‘aa’.

Note: There is no need to consider the delimiting of characters ‘.’ and ‘*’

Implement a simple regex parser with operator support for '.' and '*'.

Basic Regex

Say you are given a text document in the form of a string with the following sentences:

Example:

Input:

<pre tabindex="0" class="chroma"><code>document = &#34;I have a nice car with a nice tires&#34;
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>
{
&#34;I&#34;:0.11,
&#34;have&#34;:0.11,
&#34;a&#34;:0.22,
&#34;nice&#34;:0.22,
&#34;car&#34;: 0.11,
&#34;with&#34;:0.11,
&#34;tires&#34;:0.11
}
</code></pre>

Write a program in python to determine the TF (<code>term_frequency</code>) values for each term of this document.

Note: Round the term frequency to 2 decimal points.

Write a program in python to determine the TF values for each term of a document

Term Frequency

Tell me about a data project that didn’t go the way you expected. What did you set out to do, what surprised you, and how did you handle it?

Given an array and a target integer, write a function <code>sum_pair_indices</code> that returns the indices of two integers in the array that add up to the target integer. If not found, just return an empty list.

Note: Can you do it on \(O(n)\) time?

Note: Even though there could be many solutions, only one needs to be returned.

Example 1:

Input:

<pre tabindex="0" class="chroma"><code>array = [1 2 3 4] 
target = 5 
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>def sum_pair_indices(array, target) -&gt; [0 3] or [1 2]
</code></pre>

Example 2:

Input:

<pre tabindex="0" class="chroma"><code>array = [3]
target = 6 
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>Do NOT return [0 0] as you can&#39;t use an index twice.
</code></pre>

Given an array and a target integer, write a function that returns the indices of two integers in the array that add up to the target integer.

Target Indices

You are given a list of integers called <code>numbers</code>. Write a function to return any subset of <code>numbers</code> where the elements <code>sum</code> to <code>zero</code> and that does not contain the number <code>0</code>.

If there are no combinations of elements that sum to zero, return an empty list.

Example 1:

Input:

<pre tabindex="0" class="chroma"><code>numbers = [1,-2,6,7,1]
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>def zero_sum(numbers) -&gt; [1,-2,1] # only possible combination
</code></pre>

Example 2:

Input:

<pre tabindex="0" class="chroma"><code>numbers = [0,0,1,3,6,-4,-1]
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>def zero_sum(numbers) -&gt; [1,3,-4]
</code></pre>

or

<pre tabindex="0" class="chroma"><code>def zero_sum(numbers) -&gt; [1,-1]
</code></pre>

or any other subset that sums to zero and doesn’t include <code>0</code>.

Write a function to return any subset of the input list where the elements sum to zero and that does not contain the number 0.

Sum to Zero

You’re hired by a literary newspaper for an unusual project. They want you to use your data science skills to parse the most frequent words used in poems.

Poems are given as a list of strings called <code>sentences</code>. Return a dictionary of the frequency that words are used in the poem.

Your keys should be a number representing the number of times the word is used in the poem, with its value being a list of words with that frequency.

Make sure to process all words as entirely lowercase. Additionally, do not worry about parsing punctuation marks.

Note: Due to limitations with our code runner, your keys will be displayed as strings instead of integers. But you do not need to convert the keys to strings yourself

Example:

Input:

<pre tabindex="0" class="chroma"><code>sentences = [
 &#34;I love roses&#34;,
 &#34;Roses are the best&#34;,
 &#34;Roses are red violets are blue&#34;
]
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>def word_frequency(sentences) -&gt; {
 &#34;1&#34;:[&#34;I&#34;,&#34;love&#34;,&#34;the&#34;,&#34;best&#34;,&#34;violets&#34;,&#34;blue&#34;],
 &#34;3&#34;:[&#34;roses&#34;,&#34;are&#34;]
}
</code></pre>

Implement Dijkstra’s shortest path algorithm for a given graph with a known source node.

A graph format is a dictionary of nodes as key and the value is a dictionary of neighbors to that node with the distance between them as follow.

Note: set the previous node of the source node to <code>None</code>.

Example:

Input:

<pre tabindex="0" class="chroma"><code>
source_node = &#39;A&#39;

graph = {
 &#39;A&#39;: {
 &#39;D&#39;: 1,
 &#39;B&#39;: 6
 },
 &#39;B&#39;: {
 &#39;A&#39;: 6,
 &#39;D&#39;: 2,
 &#39;E&#39;: 2,
 &#39;C&#39;: 5
 },
 &#39;C&#39;: {
 &#39;B&#39;: 5,
 &#39;E&#39;: 5
 },
 &#39;D&#39;: {
 &#39;A&#39;: 1,
 &#39;B&#39;: 2,
 &#39;E&#39;: 1
 },
 &#39;E&#39;: {
 &#39;C&#39;: 5,
 &#39;B&#39;: 2
 }

 }


</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>
output_table = {
 &#39;A&#39;: {
 &#39;ShortestDistance&#39;: 0,
 &#39;PreviousVertex&#39;: None
 },
 &#39;B&#39;: {
 &#39;ShortestDistance&#39;: 3,
 &#39;PreviousVertex&#39;: &#39;D&#39;
 },
 &#39;C&#39;: {
 &#39;ShortestDistance&#39;: 7,
 &#39;PreviousVertex&#39;: &#39;E&#39;
 },
 &#39;D&#39;: {
 &#39;ShortestDistance&#39;: 1,
 &#39;PreviousVertex&#39;: &#39;A&#39;
 },
 &#39;E&#39;: {
 &#39;ShortestDistance&#39;: 2,
 &#39;PreviousVertex&#39;: &#39;D&#39;
 }
 }
</code></pre>

<img src="/s3/questions/785715d4-3305-4b9f-bdd7-33d5cf987bdb.png" alt="image"/>

Implement Dijkstra's shortest path algorithm for a given graph with a known source node.

Dijkstra implementation

You’re a data scientist at YouTube. Leadership wants to revisit how the platform measures success, not for a specific new feature, but for the product as a whole given its current state.

How would you define and measure success for YouTube? Identify your primary and secondary metrics, explain your rationale for each, and discuss how you would choose the right thresholds for any engagement-based metrics you propose.

Given a list of sorted integer lists, write a function <code>sort_lists</code> to create a combined list while maintaining sorted order without importing any libraries or using the <code>&#39;sort&#39;</code> or <code>&#39;sorted&#39;</code> functions in Python.

Example:

Input:

<pre tabindex="0" class="chroma"><code>lists = [
[1,2,3,4,5,6],
[2,5,7,8],
[3,9,10,12],
[0,1,2,8]
]
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>def sort_lists(lists) -&gt; [0,1,1,2,2,3,3,4,5,5,6,7,8,8,9,10,12]
</code></pre>

Write a function `sort_lists` to combine sorted integer lists into one sorted list without using libraries or `sort`/`sorted`

Merge N Sorted Lists

Given a list of numbers <code>nums</code> and an integer <code>window_size</code>, write a function <code>moving_window</code> to find the moving window average.

Example 1:

Input:

<pre tabindex="0" class="chroma"><code>nums = [1,2,3,4,5,6]
window_size = 3
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>def moving_window(input, window_size) -&gt; [1, 1.5, 2, 3, 4, 5]
</code></pre>

Example 2:

Input:

<pre tabindex="0" class="chroma"><code>nums = [1,2,3,4,5,6]
window_size = 4
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>def moving_window(input, window_size) -&gt; [1, 1.5, 2, 2.5, 3.5, 4.5]
</code></pre>

Given an integer array <code>nums</code>, return an array <code>answer</code> such that <code>answer[i]</code> is equal to the product of all the elements of <code>nums</code> except <code>nums[i]</code>.

The product of any prefix or suffix of <code>nums</code> is guaranteed to fit in a 32-bit integer.

You must write an algorithm that runs in <code>O(n)</code> time and without using the division operation.

<h3>Example 1:</h3>

Input:

<pre tabindex="0" class="chroma"><code>nums = [1,2,3,4]
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>def productExceptSelf(nums) -&gt; [24,12,8,6]
</code></pre>

<h3>Example 2:</h3>

Input:

<pre tabindex="0" class="chroma"><code>nums = [-1,1,0,-3,3]
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>def productExceptSelf(nums) -&gt; [0,0,9,0,0]
</code></pre>

<h3>Constraints:</h3>

<ul>
<li><code>2 &lt;= nums.length &lt;= 10^5</code></li>
<li><code>-30 &lt;= nums[i] &lt;= 30</code></li>
<li>The input is generated such that <code>answer[i]</code> is guaranteed to fit in a 32-bit integer.</li>
</ul>

Return an array where each element is the product of all numbers except the current index, without using division

Product of Array Except Self

Let’s say you’re in a supermarket.

You’ve found out that there is a huge discount on some items you want; unfortunately, you only have one bag with a certain <code>bag_capacity</code>. Each of the items has its own <code>value</code> and <code>capacity</code>, stored in lists called <code>values</code> and <code>capacities</code> contained in a dictionary called <code>items</code>.

Write a function to pick the items that maximize the total value without exceeding the bag’s capacity and return the total value.

Note: You can’t take more than one copy of each item home. Also, you do not need to fill the entire bag to capacity.

Example:

Input:

<pre tabindex="0" class="chroma"><code>items = {
 &#34;values&#34;:[2,3,1,4],
 &#34;capacities&#34;:[2, 4, 6, 5]
}

bag_capacity = 8
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>max_profit(items,bag_capacity) -&gt; 6
</code></pre>

We choose the first and last item with a total profit of 6 and a capacity of 7, which is less than the <code>bag_capacity</code>.

Write a function to pick the items that maximize the total value without exceeding the bag’s capacity

Filling Supermarket Bag

You work as a backend engineer at a growing messaging startup. The team is tasked with building a scalable messenger service that supports individual and group chats, message delivery receipts, and media attachments.

How would you architect the core messaging components using object-oriented principles?

Write a technical design document describing your approach.

Design a scalable messenger system using OOP principles and write a technical design document.

Messenger Service Design

Concurrent & Distributed Systems

You are working on a Snowflake-like analytics platform that stores query history for enterprise customers. Product managers want a feature that lets users search past queries by text, filter by metadata, and retrieve the most relevant results quickly.

Design a query-retrieval system that supports the following requirements:

<ol>
<li>Users can search by keywords appearing in the SQL text, for example <code>join</code>, <code>customer_id</code>, or <code>date_trunc</code>.</li>
<li>Users can filter by <code>user_id</code>, <code>warehouse_name</code>, <code>start_time</code> and <code>end_time</code>, and <code>status</code> such as <code>SUCCESS</code>, <code>FAILED</code>, or <code>CANCELLED</code>.</li>
<li>Results should be ranked by relevance, with exact keyword matches ranked higher than partial matches.</li>
<li>The system should return the top <code>k</code> results, sorted by relevance and then by most recent execution time.</li>
<li>The system must scale to billions of query records and support low-latency search.</li>
</ol>

Design a query-retrieval system for an analytics platform

Design a query-retrieval system

AI & Agentic Systems

<h1>Binary Tree Validation</h1>

You are given the root of a binary tree. You need to determine if it is a valid binary search tree (BST).

A valid BST is defined as follows:

<ul>
<li>The left subtree of a node contains only nodes with values less than or equal to the node’s value.</li>
<li>The right subtree of a node contains only nodes with values greater than or equal to the node’s value.</li>
<li>Both the left and right subtrees must also be binary search trees.</li>
</ul>

Given the function <code>def is_valid_bst(root: Node) -&gt; bool:</code>, return True if the binary tree is a valid BST. Otherwise, return False.

<h3>Example:</h3>

Input:

<img src="/s3/questions/9664817c-3e12-4a40-9236-8382b13f55a0.png" alt="image"/>Converted Binary Tree.png

Output:

<pre tabindex="0" class="chroma"><code>def is_valid_bst(Node(3)) -&gt; True
</code></pre>

Given the root node, verify if a binary search tree is valid or not.

Binary Tree Validation

You’re given a table that represents search results from searches on Facebook. The <code>query</code> column is the search term, <code>position</code> column represents each position the search result came in, and the <code>rating</code> column represents the human rating from 1 to 5 where 5 is high relevance and 1 is low relevance.

Each row in the <code>search_events</code> table represents a single search with the <code>has_clicked</code> column representing if a user clicked on a result or not. We have a hypothesis that the CTR is dependent on the search result rating.

Write a query to return data to support or disprove this hypothesis.

Example:

Input:

<code>search_results</code> table

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

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

<tr>
<td><code>result_id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>position</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>rating</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
<code>search_events</code> table

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

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

<tr>
<td><code>query</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>has_clicked</code></td>
<td>BOOLEAN</td>
</tr>
</tbody>
</table>

Write a query to analyze whether CTR depends on search result rating using click data

Search CTR

Analytics

Let’s say that you’re a data scientist working for Facebook.

You’ve been asked to generate a machine learning model that can map the legal first name of a person to likely nicknames they might have.

How do you go about designing this model?

Given a string <code>s</code>, imagine reading through it one character at a time, as if you’re following a path made of letters. As you move forward, you want to keep track of the longest stretch you can travel without encountering the same character twice. String <code>s</code> consists of English letters, digits, symbols and spaces.

Your task is to find the length of the longest substring without duplicate characters — in other words, the longest continuous portion of <code>s</code> where every character is unique and no repeats interrupt the journey.

<h3>Example 1:</h3>

Input:

<pre tabindex="0" class="chroma"><code>s = &#34;xyzxyzyyxxxx&#34;
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>def longest_substring_length(s) -&gt; 3
</code></pre>

Explanation: The answer is <code>&#34;xyz&#34;</code>, with the length of 3. Note that <code>&#34;yzx&#34;</code> and <code>&#34;zxy&#34;</code> are also correct answers.

<h3>Example 2:</h3>

Input:

<pre tabindex="0" class="chroma"><code>s = &#34;xxxxxxxxxxxxxx&#34;
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>def longest_substring_length(s) -&gt; 1
</code></pre>

Explanation: The answer is <code>&#34;x&#34;</code>, with the length of 1.

<h3>Constraints:</h3>

<ul>
<li><code>0 &lt;= s.length &lt;= 5 * 10^4</code></li>
</ul>

The Longest Journey

Imagine you have been given an array of integers, and a query number <code>k</code>. Your task is to write a function that finds all the triplets in the array that sum up to the query number <code>k</code>.

Let’s illustrate this with some examples:

Example 1:

Input:

<pre tabindex="0" class="chroma"><code>nums = [1, 2, 3, 4, 5]
k = 6
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>count_triplets(nums, k) -&gt; 1
</code></pre>

In this case, there is only one triplet that sums up to 6: (1, 2, 3).

Example 2:

Input:

<pre tabindex="0" class="chroma"><code>nums = [10, 10, 20, 30, 40]
k = 60
</code></pre>

Output:

<pre tabindex="0" class="chroma"><code>count_triplets(nums, k) -&gt; 3
</code></pre>

In this case, there are three triplets that sum up to 60: (10, 10, 40), (10, 20, 30), and (10, 20, 30).
The value 10 can be retrieved as <code>nums[0]</code> or <code>nums[1]</code>, therefore resulting in two triplets with the same value.

Write a function that returns the number of triplets in the array that sum to `k`.

Triplet Counting

How do you sort a 100GB file when you are constrained to only 10GB of RAM?

Explaining optimizations needed to sort a 100GB file with 10GB RAM

External Sorting

You work as a machine learning engineer at a cloud-based SaaS company. The company wants to automate the process of building, training, and deploying image classification models using datasets stored in S3. The models must be deployed on Kubernetes (EKS), and the entire workflow should be automated with a CI/CD pipeline.

How would you design this end-to-end system?

Design an automated pipeline for building, training, and deploying image classification models using S3 and EKS.

Image Classification Pipeline

ML Ops

Let’s say that we want to improve the “search” feature on the Facebook app.

We want to specifically improve search results for people looking for things to do in San Francisco.

What would you investigate and what metrics would you come up with to understand if the current functionality in the search was performing well?

Let’s say we’ve proposed a new analytics dashboard to a client, but after reviewing our design and data sources, the client says the solution doesn’t meet their needs and pushes back on several key features.

How would you approach the conversation to negotiate alternative solutions, and what steps would you take to ensure disagreements are handled constructively so we can still reach a successful outcome?

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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