Low-Level Atlas II Index

Nine branches across six phases, every one of them a real system built from scratch in C. This atlas assumes Low-Level Atlas I is already done — the machine model, C, pointers and memory, assembly, the toolchain, systems programming, concurrency basics, and a small OS. Nothing here re-explains that; everything here builds on it.

01 · Warm-up Builds

• Shell from Scratch — fork/exec, pipes, redirection, signals, job control.
• malloc from Scratch — free lists, coalescing, sbrk vs mmap.
• Regex Engine from Scratch — Thompson NFA, no exponential backtracking.

02 · Data & Serialization

• Mini Git — content-addressed object store, the commit graph, a working .git.

03 · Networked Systems

• HTTP Server from Scratch — raw sockets, hand-parsed HTTP/1.1, epoll/kqueue.

04 · Concurrency & Performance II

• Concurrency in Practice — thread pools, lock-free vs locks, real load benchmarking.

05 · The Database Engine

• KV Store & Durability — a B-Tree, fsync, WAL, crash recovery. v0 → v1.
• Relational Layer & Query Engine — tables, indexes, SQL, transactions. v2 → v3.

★ · Always Active

• Craftsmanship Low-Level II — testing parsers, concurrency bugs, fuzzing, TDD on disk-backed state.

Reference

• Reference Registry — sources, tools, and the codecrafters/build-your-own-X hubs this atlas draws from.