About

I'm Donny MacPhail, an engineer in Boston focused on building stable, scalable systems and clean architecture. In my 9-5 I work on a React-based sales app and a backend platform that I've been modernizing over time. The work is a mix of new features, reliability improvements, and steady reduction of tech debt. I care a lot about keeping things simple, shipping incrementally, and leaving the codebase better than I found it.

Outside of work I'm building simmr.io, an AI-assisted food management and meal planning app focused on pantry tracking, sharing, and lowering friction in everyday cooking. I use Claude Code as a pair programmer on it, which has changed how I think about shipping solo projects. It's my sandbox for product experiments, LLM workflows, and thoughtful UX. It's also where I stress-test ideas about agentic systems before writing about them here.

I graduated from Wentworth Institute of Technology in Boston, and I'm currently based in the city. I enjoy pragmatic engineering, system design, and the occasional vibe-coding session. When I'm not writing code I'm usually cooking, reading, playing with my dog Ted or spending time with my wife Jenn.

This site is where I share engineering notes, product thinking, and experiments in AI and system design. Most of what I write comes directly from problems I've hit at work or on simmr. If you're building in similar areas, I'd love to compare notes.