Free · open · one structured queue
Prepare for the whole interview, not just the coding round.
Coding, SQL, machine learning, math, agents/LLMs, and system design — organized by pattern, with a practice editor, per-track progress, and links to the original problems. Everything runs in your browser; your progress stays on your device.
Tracks
Coding
Data-structures & algorithms, grouped by pattern.
0 / 272 problems
SQL & Databases
Query patterns, window functions, engine internals.
0 / 36 problems
Machine Learning
Features, models, training, metrics, debugging.
0 / 9 lessons
ML System Design
Framework + real ML system walk-throughs.
0 / 11 lessons
Agents & LLMs
LLM internals, agent design, tools, RAG, evals.
0 / 18 lessons
GenAI System Design
Designs from smart-compose to text-to-video.
0 / 10 lessons
System Design
Classic distributed-systems design.
0 / 29 lessons
Object-Oriented Design
OOD problems and modelling.
0 / 14 lessons
Math
Probability, statistics & inference, linear algebra.
0 / 3 lessons
Case Studies
Worked, end-to-end case studies.
0 / 9 lessons