About me

I'm John Costa, a software engineer based in Oakland, California. I've spent over a decade at startups as an individual contributor, tech lead, and engineering director. My work has spanned site reliability, full-stack feature development, infrastructure, and team leadership. I go wherever the problem is.

I'm a generalist by nature. I've shipped production code in TypeScript, Ruby, Python, Go, and Rust. I've built frontends in React, backends in Rails and Node, and infrastructure on AWS and Cloudflare. I care less about the stack and more about whether the thing we're building actually solves the problem. At every company I've worked at, I've ended up crossing into product and design because I think the best engineers understand what they're building and why.

I'm an active open source contributor with merged pull requests in projects like ink, Homebrew, Biome, and Nickel. I contribute because I use these tools and want them to be better. I also build my own: Claude Code plugins, trading systems, and developer tools. I write regularly about engineering and AI at blog.jcosta.tech.

Right now I'm focused on AI-augmented development. Not using AI as a shortcut, but as a way to work across more of the stack with higher quality. Design, product thinking, and engineering are converging, and I want to be at that intersection. I'm looking for teams that build with intention and ship things that matter.