$ whoami
Xavier Fabregat
Physicist turned engineer.
Full-stack software engineer based in Barcelona with 4+ years shipping production systems — from video-analytics SDKs used by broadcasters to a pile of side projects spanning Rust CLIs, physics engines and AI tooling. I like hard problems and small, sharp tools.
01 — about
From wavefunctions
to web players.
I studied theoretical physics & computational modelling at the Universitat de Barcelona, then pivoted full-time into software during the pandemic. The physics never really left — it's why I gravitate toward simulation, performance and systems that have to be correct, not just working.
These days I build the NPAW Plugin JS SDK — a TypeScript monorepo delivering video analytics, CDN balancing and P2P delivery across browsers, Smart TVs and React Native. Before that I led a flagship product launch that grew adoption 50%+.
Off the clock I'm a relentless prototyper: I ship Rust tools, RAG systems, game engines and the odd location-based game — usually to scratch an itch or learn something new.
02 — experience
Where I've shipped.
Software Developer · Nice People At Work
Sep 2025 — PresentDevelop & maintain the NPAW Plugin JS SDK — an 8+ package TypeScript monorepo for video analytics, CDN balancing and P2P delivery, in production with broadcasters. Built adapters for 20+ web/native players, own the multi-CDN build & release pipeline (AWS + GCP, UMD/ESM/ES5 bundles), and work directly with integration partners.
Lead → Senior → Software Developer · Codeworks
Apr 2022 — Jun 2025Led the end-to-end build of flagship product Self Paced (+50% adoption). Drove a Svelte migration for a 200%+ performance boost, championed a company-wide testing strategy (0 → 50%+ coverage), optimised SQL queries, and mentored junior engineers in TDD.
Software Developer · Nanji
Nov 2021 — Feb 2022Set up scalable AWS backend infrastructure, drove a JavaScript → TypeScript migration, and lifted test coverage by 95% across 100+ frontend and backend modules.
BSc Physics · Universitat de Barcelona
2017 — 2021Specialised in theoretical physics and computational modelling.
03 — selected work
Things I've built for fun.
A sample from the lab — most are open source on GitHub.
04 — toolbox
The stack I reach for.
05 — contact
Let's build something.
Open to interesting problems, good teams, and the occasional mad side project. Drop me a line.