Interview prep
Programming Interview Questions and Answers
Concise, accurate answers to the questions interviewers actually ask — grouped by level, with short code samples and coding exercises. Every answer is written to be said out loud in an interview, and every page is static and free to read.
Topics
JavaScript interview questions
Closures, the event loop, promises, prototypes, ES2024+ and 7 coding exercises.
41 questions
React interview questions
Hooks, rendering, Server Components, use(), Actions and coding exercises.
35 questions
Python interview questions
Mutability, decorators, generators, the GIL, asyncio and coding exercises.
40 questions
System Design interview questions
A 7-step framework, core concepts, 12 classic problems and LLD questions.
33 questions
TypeScript interview questions
Types vs interfaces, generics, narrowing, utility and conditional types.
25 questions
SQL interview questions
Joins, window functions, CTEs, indexes, transactions and query exercises.
25 questions
Java interview questions
OOP, collections, streams, records, virtual threads, JVM and GC.
25 questions
C# interview questions
Value vs reference types, async/await, LINQ, records and C# 12 features.
25 questions
C++ interview questions
RAII, smart pointers, move semantics, virtual dispatch, templates and C++20.
25 questions
Also useful for coding rounds
- Data structures and algorithms guide — Big-O, the core structures and a study plan, with Python examples.
- Cheat sheets — quick syntax revision for Python, SQL, Git, TypeScript and more.
- Developer glossary — one-paragraph definitions of terms like CAP theorem, sharding and idempotency.
Interview questions FAQ
How to get the most out of these pages
How are these interview questions organised?
Each topic page groups questions into beginner, intermediate and advanced sections followed by coding exercises. System design is organised differently: a seven-step interview framework, core concepts, 12 classic problems and low-level design questions.
Are the answers up to date?
Answers target current language versions — ES2024+ JavaScript, React 19, Python 3.12+, Java 21, C# 12 and C++20 — and each page shows the date it was last reviewed.
What is the best way to use these questions?
Read the question, answer it aloud as you would in an interview, then open the answer to compare. Write the coding exercises from memory without an editor. Depth beats volume: being able to explain each answer clearly matters more than the number of questions you have seen.
Which topic should I start with?
Start with the language the job description names, then SQL if the role touches data, and system design for mid-level and senior roles. Pair any of them with the data structures and algorithms guide for coding rounds.