Interview Questions
Questions grouped by topic, each with a clear answer you can expand, plus code, diagrams and the follow-ups to expect.
- 1
Pick a topic
Browse questions by technology or interview type.
- 2
Try it first
Read the question and answer it in your head, or out loud.
- 3
Open the answer
Compare with a clear answer, code and diagrams, plus common follow-ups.
Topics
New topics are on the way. Python is free for everyone; the others need a free account.
Python
Core language, data structures and writing Pythonic code.
JavaScript
Closures, this, async code and the event loop.
SQL
Joins, grouping, window functions and indexes.
Git
Branching, merging, rebasing and fixing mistakes.
System Design
Design scalable systems, one building block at a time.
Behavioral
Tell clear, structured stories about your work.
LLMs & AI
Prompting, RAG, agents and evaluating AI apps.