Learn C, algorithms, systems, and networking the way the machine sees it

C fundamentals

Algorithms & data structures

Every fundamental data structure, implemented in C, visualized in memory.

Systems programming

Processes, syscalls, memory, concurrency. How your program talks to the OS.

Networking

Sockets, packets, NAT, and the kernel’s network stack. How bytes leave your process and arrive in another one, on another machine.

Build a mesh VPN

A Tailscale-style overlay network, written in C from scratch. TUN device, encrypted UDP, a coordination server, NAT traversal, a relay. Every lesson leaves you with something that runs.

Vector database from scratch

An embedded, single-file vector search engine for on-device AI features. Storage, quantization, filtering, HNSW.