115 AI systems challenges

Build modern AI from scratch.

Implement the internals of modern AI — from attention to RLHF, diffusion models, and distributed training. Real PyTorch tests, instant feedback.

Instant Feedback

Pass/fail per test case, execution time, and error messages — right after you submit.

Real Tests

Tests run against actual PyTorch — no mocks, no shortcuts. If it passes here, it works.

Progress Tracking

Track solved problems, best times, and attempt counts across sessions.

Easy

Medium

Hard