🔩 What this is

Under the Hood opens up the systems you use every day — one system at a time — and rebuilds the core mechanism small enough that you can read it, run it, and break it yourself.

Each teardown is reconstructed from a company’s public engineering blog, and:

• 🧩 starts from the problem the system solves and builds the architecture up one decision at a time;
• 🔬 names the algorithms and data structures underneath, and explains why each choice holds;
• 💻 ships a runnable prototype in the companion repo;
• 🧾 is an honest reconstruction — inferred from public sources, clearly cited, never claiming to be a company’s real source code, and not affiliated with the companies discussed.

Spotted something wrong? These are reconstructions — if a detail disagrees with the original source, trust the source, and please open an issue so it can be corrected.