Build production-grade APIs, solve system design problems, and prove your skills with automated testing across multiple difficulty levels.
Build file storage APIs, distributed caches, message queues, and more. Challenges inspired by real engineering problems.
Each challenge has multiple difficulty levels. Start simple, then unlock harder test suites as you progress.
Submit your solution and get results once the run finishes. Our automated pipeline builds, runs, and tests your code.
Explore challenges by difficulty. Read the requirements, API specs, and test cases before you start.
Use any supported language. Build your solution locally following the provided specifications.
Upload your solution as a zip file. Your submission is queued, built and tested; results arrive once the run finishes. Pass to unlock the next level.
Browse the available challenges and start coding today.