John Costa — Engineer, leader, builder.
I turn ambiguity into shipped products. I've spent over a decade in startups as an IC, tech lead, and engineering director, working on everything from site reliability to full-stack feature development. I go wherever the work needs me and partner across teams to find opportunities that wouldn't exist if no one was looking. Today I'm pushing AI-augmented building and contributing to open source tools that give back.
Product-Focused
I start with the problem, not the technology. Every line of code should ship value to the customer. I think in incremental streams, not big bangs.
Full-Stack Generalist
Architecture to UI, Rails to React, infrastructure to design. A decade of wearing every hat in startups means I can go wherever the work needs me.
AI-Augmented Builder
Design, product, and engineering are converging. I'm leaning into that future, using AI tools to build faster and with broader reach than any single discipline.
Open Source
Building in the open
Contributing to projects developers rely on
Recently merged
fix(server): don't redirect error responses from #[get] server functions
DioxusLabs/dioxus#5429
Add context field to OpenRouter, MistralAI, and OpenAI models
HeyPuter/puter#2653
test: add unit tests for useMenuEntriesState and useQRCode composables
activist-org/activist#2063
Add oss-autopilot plugin
rohitg00/awesome-claude-code-toolkit#105
bundle: add base class helpers and DRY up extension executable handling
Homebrew/brew#21854
My projects
oss-autopilot
An AI-powered autopilot for managing open source contributions. It tracks PRs, responds to maintainers, discovers new issues, and helps maintain velocity. Built as a Claude Code plugin that makes sustained OSS contribution practical.
alpaca-trader
A self-evolving automated trading system that combines sentiment analysis, insider signals, and AI-driven position management. It learns and adapts over time.
mermaid-to-pdf
A CLI and MCP tool that converts Markdown files with Mermaid diagrams into PDF. Works standalone or as an AI-accessible tool via Model Context Protocol.
Open source isn't just about building tools. It's about giving back. I volunteer my engineering skills through organizations like Ruby for Good and Activist, where code can make a real difference for communities that need it. These numbers update automatically via oss-autopilot.
Writing
Recent thinking
Automate Your Life With Cron Jobs, GitHub Actions, and Telegram
Scheduled jobs, free tools, and a little AI can quietly run a surprising amount of your life
Your Portfolio Site Deserves a Pipeline
I rebuilt my personal site as plain HTML with zero frameworks. Then I gave it a real data pipeline so it never goes stale.
Claude Code Tips and Tricks
For AI-Assisted Engineering
The Biggest Bottleneck in Enterprise Software Isn't Technical
The Coordination Tax
Why Functional Programming Is the Most Important Skill for the AI Era
What type-driven design, declarative thinking, and domain modeling have to do with AI
How to Have a Career in 2026
A step-by-step guide for leveraging AI in any job function
What It Takes to Be a Software Engineer in 2026
AI made implementation easier. Here's how to stay valuable.
AI Drives, You Direct
How I finally started getting PRs merged
Why AI-Assisted Development Feels Like Engineering Management
How years of code review prepared me for working with Claude
AI-Assisted Home Automation in 2026
With Home Assistant and Claude Code
Modeling React State as a Finite State Machine
A modern approach using TypeScript discriminated unions and hooks
Building a Traffic Light React App
With State Machines and Domain Driven Design
Collaborate
Work with me
AI Adoption
Hands-on integration of AI tooling into real workflows. Claude Code, MCP plugins, and custom automation that ships value on day one.
Product Development
Full-stack engineering from prototype to production. Over a decade taking rough ideas and turning them into shipped products across startups of every size.
Open Source Strategy
Build a contribution strategy, set up sustainable workflows, and make your OSS presence something that attracts talent instead of gathering dust.
Engineering Leadership
Scaling code review and mentorship across growing teams. SRE background in reliability, observability, and the operational discipline that lets teams ship with confidence.