I build ML infrastructure and distributed systems.
I’m John Gerassimou, a senior software engineer based in New York. At Meta, I work on infrastructure that supports feed recommendations across Facebook, Instagram, and Threads.
Before Meta, I built data platforms, backend systems, and cloud infrastructure at Unity, Askuity, Badal.io, and LCBO. Earlier in my career, I worked on big data platforms for IoT applications at York University’s Adaptive Software Research Lab.
I’ve also taught programming and data analytics, spoken about streaming systems at developer events, contributed to open source, and mentored engineers and students. Those experiences shaped how I work. I communicate clearly and build systems that are practical to operate.