Book Image

Cracking the Data Science Interview

By : Leondra R. Gonzalez, Aaren Stubberfield
Book Image

Cracking the Data Science Interview

By: Leondra R. Gonzalez, Aaren Stubberfield

Overview of this book

The data science job market is saturated with professionals of all backgrounds, including academics, researchers, bootcampers, and Massive Open Online Course (MOOC) graduates. This poses a challenge for companies seeking the best person to fill their roles. At the heart of this selection process is the data science interview, a crucial juncture that determines the best fit for both the candidate and the company. Cracking the Data Science Interview provides expert guidance on approaching the interview process with full preparation and confidence. Starting with an introduction to the modern data science landscape, you’ll find tips on job hunting, resume writing, and creating a top-notch portfolio. You’ll then advance to topics such as Python, SQL databases, Git, and productivity with shell scripting and Bash. Building on this foundation, you'll delve into the fundamentals of statistics, laying the groundwork for pre-modeling concepts, machine learning, deep learning, and generative AI. The book concludes by offering insights into how best to prepare for the intensive data science interview. By the end of this interview guide, you’ll have gained the confidence, business acumen, and technical skills required to distinguish yourself within this competitive landscape and land your next data science job.
Table of Contents (21 chapters)
Free Chapter
1
Part 1: Breaking into the Data Science Field
4
Part 2: Manipulating and Managing Data
10
Part 3: Exploring Artificial Intelligence
16
Part 4: Getting the Job

Analyzing subqueries and CTEs

SQL subqueries, also known as nested queries or inner queries, are queries that are embedded within the context of another SQL query. They are powerful tools for performing complex data manipulations that require one or more intermediary steps – that is, they are used for performing data manipulation operations that require multiple steps or depend on the result of an intermediary query.

That might sound complex and, indeed, subqueries can easily get very complicated. But once you know the rules of engagement, you’ll soon see that they’re very doable. Before implementing a subquery, ask yourself the following:

  • Where am I starting?
  • Where am I going?

If you can answer these two questions, you’ve won half the battle. The other half is determining what steps need to take place to get from point A (existing data) to point B (desired data). In this section, we will learn how to navigate multi-step queries with...