Hey, I'm Nikhil Sahani.
I'm a Senior Product Engineer with 7+ years of experience, mostly building backend systems. I like working on features from start to finish, but I care a lot about the backend side: keeping things fast, handling scale, and making sure services don't break.
I started playing with code and computers long before I worked in tech, mostly just curious about how things worked under the hood. That never really changed. I still like knowing how software works at a lower level instead of just treating it like a black box.
Lately, I also spend time with AI: adding models into backend pipelines and building small, useful tools that help solve day-to-day problems.
I prefer simple setups over complicated ones. The goal is always to write clean code, keep systems easy to maintain, and build things that run quietly without drama.
A selection of production tools and systems experiments. Some built to solve user problems; others built to dissect protocols, memory layout, and runtime mechanics from scratch.
Local-first, zero-knowledge browser password vault. Explores air-gapped secret isolation using the Web Crypto API, AES-256-GCM authenticated encryption, and deterministic 12-word BIP-39 recovery phrases. Persisted in client-side IndexedDB with zero tracking and zero server dependencies.
Custom heap memory allocator implemented in pure ANSI C providing malloc, free, realloc, and calloc. Built to understand memory alignment, heap fragmentation, and chunk headers from scratch; verified against real Linux binaries via dynamic linker interposition (LD_PRELOAD).
Minimal RFC 1459 IRC client written from scratch in ANSI C over raw POSIX/BSD sockets. Handles direct TCP streams, packet framing, non-blocking I/O polling, and keep-alive ping/pong loops strictly at the system call boundary without third-party network libraries.
Early automated WhatsApp cryptocurrency micro-tipping bot (2015). Built on reverse-engineered WhatsApp protocol layers via Yowsup, multi-signature transaction APIs, and stateful ledger tracking in MySQL to explore conversational payments before official APIs existed.
The canonical systems programming text. Terse, rigorous, and foundational for understanding memory layout, pointer mechanics, and low-level discipline.
Where it all began. The book that introduced me to coding before any formal computer science education. Broke down complex machine concepts with zero pretension and sparked my lifelong fascination with computers.
The modern bible for backend and storage systems. Unpacks replication anomalies, consensus algorithms, partition tolerance, and transactional invariants in production.
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