Codable: Code Challenges

Ten languages. Daily practice. Sharpen your skills in Swift, Python, Rust, Go, and more with hands-on challenges from fundamentals to concurrency.

Codable turns programming practice into a habit. Solve focused challenges in ten languages — from your first data structure to lock-free concurrency — and build real fluency one problem at a time.

WRITE REAL CODE IN 10 LANGUAGES C, C++, C#, Go, Java, JavaScript, Python, Rust, Swift, and TypeScript. Switch languages anytime — solve the same challenge in Python today and Rust tomorrow.

GO DEEPER THAN SYNTAX Challenges span the topics that actually make you a better engineer: • Fundamentals and string manipulation • Data structures and algorithms • Recursion and functional programming • Object-oriented design and generics • Error handling, concurrency, and memory management

BUILT FOR EVERY STAGE New to programming? Start with fundamentals and level up steadily. Experienced? Jump straight into concurrency, memory management, and the problems that show up in technical interviews.

PRACTICE THAT STICKS Short, focused challenges designed to fit into a daily routine — because fluency comes from reps, not marathons.

Download Codable and start mastering your chosen language!