Tutorials
Explore 7 tutorials on development.
A URL Reaches Your Server. What Happens Next?
Build one small API from route to response, then see when a database and cache join the request.
How LLMs Work: Build One Small Enough to Understand
Follow a tiny next-token predictor until the logic behind modern language models becomes clear.
How the Web Works
Follow one page visit from the address bar to the pixels on your screen.
Designing LeetCode
A repeatable framework for system design, breaking down client-to-backend architecture, isolated code execution, and high-concurrency leaderboards.
Database Sharding
How splitting a database across machines works, how to choose the key you cannot change later, and the four cheaper fixes almost everyone should try first.
The OSI Model
The seven layers, which of them actually exist in a real stack, and how to use the model to find out why a request is failing.
Horizontal vs Vertical Scaling
What each one actually costs, when to reach for which, and the one property of your code that decides whether you have a choice at all.