Algo150: learn data structures and algorithms one problem at a time
Algo150 is a free practice workspace for coding interviews. Solve 150 classic problems in the browser in JavaScript, TypeScript or Python. Every problem has five hints that build up to the answer, an explained solution with a traced example, and reviews scheduled so that it sticks. No account is needed: progress stays in your browser, and an account keeps it in sync.
Read the library
- Problems150 classic coding interview problems, each with five hints, an explained solution and code in JavaScript, TypeScript and Python.
- PatternsThe 42 solving patterns those problems use, each taught on a small worked example.
- Machine learning36 Python lessons from the math to a small GPT you train yourself.
- AI engineering12 labs on retrieval, tool use and evaluation, in JavaScript or Python.
- Interview prepFrontend interviews: 140 questions with model answers, 36 coding labs, 8 system design prompts and 10 timed builds.
Free to use. An optional year, $19 paid once, adds read-aloud and narrated walkthrough videos. Buy a year.
Questions: [email protected]