80 Data Engineering Interview Questions: SQL & Python Guide [2026]
Master SQL and Python with These Essential Data Engineering Interview Questions [2026]
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I'm Varchasv, a Data Engineer working on enterprise data integration.
Currently on a 90-problem challenge to level up my technical skills and switch to a more development-focused role.
What I'm doing:
- Solving 2 Leetcode problems daily (SQL + DSA).
- Blogging about each problem.
- Building in public.
My Goal - Land a better data engineering role by mid-2026.
Follow my journey !!
Hi everyone, this is a list of hand-picked data engineering, DSA, and SQL questions that you might face in your next interview. I originally made this list for my own practice, but as we all know, sharing is caring, so enjoy the list and let me know if I should update anything.
SQL - Bread and Butter
SQL is undoubtedly the most important skill to have as a data engineer, so we are going to focus on this first. We will go through three different levels of problems: Basics, intermediate, and Advanced, covering a total of 50 questions.
SQL Basics - 15 questions to help you build a strong foundation in SQL.
SQL Intermediate - 25 questions will challenge your thinking and enhance your skills.
SQL Advanced - 10 questions focusing a bit more on FAANG companies.
FYI - Some of these questions are paid, but there are many ways to get around it 😊.
Python - Cherry on top
As a data engineer, Python is the second most important skill after SQL. For data engineering companies, there's no need to solve 150+ problems. They mainly focus on easy and medium questions.
There are only 30 questions in my DSA Python list, and they are divided as follows.
Array and Hashing (8 problems).
Strings (4 problems).
Linked Lists (3 problems).
Trees (5 problems).
Binary Search (3 problems).
Dynamic Programming (4 problems).
Graphs (3 problems).
Let’s Get to Work
The difference between a junior and a senior Data Engineer often comes down to how they handle the "Advanced" scenarios in this list. Don't just solve these; master the logic behind them so you can handle any curveball a 2026 recruiter throws your way.
How to Participate
Bookmark this list: You’ll be coming back to it often over the next few weeks.
Start Today: Pick the first 5 SQL Basic questions.
Show Your Work: Share your daily progress on LinkedIn or X (Twitter). Mention what you learned or a specific logic that tripped you up.
Join the Conversation
I’ll be posting my own solutions and deep-dive blogs daily. Use the hashtags #DEQuest and #BuildInPublic so I can find your posts, cheer you on, and answer your questions.
Which topic are you most nervous about—Advanced SQL or Python DSA? Drop a comment below, and let’s tackle it together.
The interview is just a conversation about problems you've already solved. Let’s get started!