Harshal Sawant

I'm a backend and systems engineer from Mumbai, India. I got into programming the hard way — Android rooting, kernel modules, and digging into Linux internals — and never really stopped going deeper.

These days I build low-latency backend services, distributed systems, and developer tooling, mostly in Rust and Go. I care about the things most people abstract away: scheduler behavior, memory pressure, and what actually happens under the hood when your system is under load.

I built and maintain androidtweaker, a shell-driven optimization toolkit for rooted Android devices — runtime tuning, repeatable profiles for CPU, memory, and background tasks, built for easy long-term maintenance.

I also built coretaskoptimizer, a native C++ root module that applies CPU affinity, scheduler policy, and I/O priority to critical Android system tasks at boot, with minimal overhead.

Currently building shrty, a URL shortener with click analytics, geo-IP lookup, and a Redis-fronted Postgres cache layer designed to survive viral-link hot keys.

And ratelock, a per-tenant API gateway built on atomic Redis Lua token buckets, with plan-aware quotas and standard X-RateLimit headers.

Software Engineer · Freelance · Remote · 2024 – Present

–Built backend services in Rust with Actix Web, focused on fast and reliable request handling.

–Built REST APIs end to end — routing, auth, validation, and error handling.

–Ran PostgreSQL, Redis, Docker, and CI/CD to keep services stable and easy to maintain.