Implementing core system utilities and algorithms from scratch in C. Features manual memory management, finite state machines, and raw stream processing without high-level abstractions.

LD_PRELOAD interposer wrapping all malloc‑family calls, embedding canary‑guarded headers to catch double‑frees/overflows, leak‑reporting at exit with thread‑ and fork‑safety.

A secure authentication simulation in C implementing defensive programming techniques to prevent buffer and integer overflows.