Hi — I'm Jon.

I'm a senior/staff product engineer, educator, and author of two Node.js books with Manning and O'Reilly. I build AI-powered consumer products and the platforms behind them: at Meta I led UI architecture and the 8M+-user rollout of Meta AI on Quest, and earlier led messaging and ads infrastructure for Messenger. Before that I built ML-backed analytics products at Bloomberg.

Today I'm building agentic healthcare software at Marlow. I've spent most of my career as a tech lead: setting technical direction, running work across teams and with design, product and legal, and mentoring the engineers who ship it. I care about making complex ideas easier to understand, whether that happens through code, teaching, or writing.

I also run Hacky Apps, where I consult on engineering, product, and custom application development. See my portfolio for the full picture.

Elsewhere — podcast (JavaScript), Twitch: Node & web apps, Twitch: APIs.