Interview Cracker
Interview prep that explains why an answer is right. Every question has a written answer, every challenge has a commented solution with its complexity, and every concept links to a small runnable program.
Interview Prep
38 subject question banks with full written answers — data structures, algorithms, databases, OS, networking, concurrency, system design, language-specific and behavioural.
Coding Challenges
Problems grouped by the pattern that solves them, each with a hint, a tested solution and its complexity.
Daily Challenges
One focused problem per day, with the answer collapsed so you can attempt it first.
150 Runnable Examples
One concept per file across 13 languages. Most print their own expected output, so you can change a line and see what happens.
Start here
If your interview is soon, read the study plans — there is a one-week and a four-week version. Then drill the challenges by pattern, because recognising the pattern is the part that transfers.
What makes this different
- Every code snippet has been executed, and cross-checked against a brute-force reference on randomised inputs where practical.
- Complexity is stated and justified, including the space cost of recursion.
- Trade-offs over rules. Where there is no single right answer, the answer explains the choice.
- No invented company attributions. Nothing here claims to be "asked at" any employer — those claims are not verifiable.
Found a mistake? Edit this page on GitHub.