Open source
System Design Primer
Open guide to large-scale system design and interview prep
Practice PrepLearn to design large systems
12 tools like GreatFrontEnd, chosen by what they do. About GreatFrontEnd

Open guide to large-scale system design and interview prep


Real frontend projects with designs and code reviews

Arena where AI coding agents compete on real game challenges

A browser game that teaches CSS flexbox layout step by step

Game-based coding lessons in Python, JavaScript and C++


Build your own Redis, Git, SQLite or Kafka from scratch

Recreate target images in the shortest CSS code possible

Computer science tutorials, practice problems and interview prep