Prepare for and practice interview questions from Infomagnus.

Infomagnus Interview Questions

<p>we approach every project, regardless of size, as if our business depended on it. because it does! we treat every relationship, regardless of level, with respect and humility. our commitment to our employees’ aspirations are unwavering. we embrace our communities and look for ways to give back. infomagnus was built to provide an environment where passion is celebrated. where personal time is respected and embraced. where hard work is rewarded. in a business driven by people, disagreement and failure will happen. we encourage disagreements and passionate discussions to arrive at the best solutions and decisions. failure will happen. we will take responsibility and do the right thing in every situation. we will share the experience broadly and move on. our goal is to build an organization for the ages. for more information, please visit us at http://www.infomagnus.com or send an email to info@infomagnus.com</p>

we approach every project, regardless of size, as if our business depended on it. because it does! we treat every relationship, regardless of level, with respect and humility. our commitment to our employees’ aspirations are unwavering. we embrace our communities and look for ways to give back. infomagnus was built to provide an environment where passion is celebrated. where personal time is respected and embraced. where hard work is rewarded. in a business driven by people, disagreement and failure will happen. we encourage disagreements and passionate discussions to arrive at the best solutions and decisions. failure will happen. we will take responsibility and do the right thing in every situation. we will share the experience broadly and move on. our goal is to build an organization for the ages. for more information, please visit us at http://www.infomagnus.com or send an email to info@infomagnus.com

Overview

A/B Testing

Algorithms

Analytics

Machine Learning

Probability

Product Metrics

Python

Statistics

Infomagnus Interview Guides

<p>Suppose there exists a new airline named Jetco that flies domestically across North America. Jetco recently had a study commissioned that tested the boarding time of every airline, and it came out that Jetco had the fastest average boarding times of any airline.</p>

<p>What factors could have biased this result, and what would you look into?</p>


<p>What could potentially bias the average boarding time in favor of an airline that only flies domestically?</p>

What could potentially bias the average boarding time in favor of an airline that only flies domestically?

Boarding Times Bias

A new airline came out as the fastest average boarding times compared to other airlines.  What factors could have biased this result and what would you look into?

<p>You are testing hundreds of hypotheses with many <em>t</em>-tests. What considerations should be made?</p>


<p>What is a key disadvantage of the F-test when compared to multiple t-tests?</p>

What is a key disadvantage of the F-test when compared to multiple t-tests?

Hundreds of Hypotheses

You are testing hundreds of hypotheses with many t-tests. What considerations should be made?

<p>The schema below is for a retail online shopping company consisting of two tables, <code>attribution</code> and <code>user_sessions</code>.</p>

<ul>
<li><p>The attribution table logs a session visit for each row.</p></li>

<li><p>If <code>conversion</code> is <code>true</code>, then the user converted to buying on that session.</p></li>

<li><p>The <code>channel</code> column represents which advertising platform the user was attributed to for that specific session.</p></li>

<li><p>Lastly the <code>user_sessions</code> table maps many to one session visits back to one user.</p></li>
</ul>

<p>First touch attribution is defined as the channel with which the converted user was associated when they first discovered the website.</p>

<p>Calculate the first touch attribution for each <code>user_id</code> that converted. </p>

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

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

<p><code>attribution</code> table</p>

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

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

<tr>
<td><code>channel</code></td>
<td>VARCHAR</td>
</tr>

<tr>
<td><code>conversion</code></td>
<td>BOOLEAN</td>
</tr>
</tbody>
</table>
<p><code>user_sessions</code> table</p>

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

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

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

<tr>
<td><code>user_id</code></td>
<td>INTEGER</td>
</tr>
</tbody>
</table>
<p><strong>Example output:</strong></p>

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

<tbody>
<tr>
<td>123</td>
<td>facebook</td>
</tr>

<tr>
<td>145</td>
<td>google</td>
</tr>

<tr>
<td>153</td>
<td>facebook</td>
</tr>

<tr>
<td>172</td>
<td>organic</td>
</tr>

<tr>
<td>173</td>
<td>email</td>
</tr>
</tbody>
</table>


Question	Topic	Difficulty	Ask Chance
Boarding Times Bias	Statistics	Medium	Very High
Hundreds of Hypotheses	Statistics	Medium	Very High
First Touch Attribution	SQL	Hard	Very High