# John Costa — jcosta.tech

> Personal site of John Costa, a software engineer and AI-augmented builder in Oakland, CA. Writing on AI-assisted engineering, open source, and building in public. 149 merged pull requests across 46+ open source repositories in 7 languages, tracked live at /contributions.html.

Every blog post is also available as raw markdown: append index.md to the post URL.

## Writing

- [The Job Search Where I Never Applied](https://jcosta.tech/writing/the-job-search-where-i-never-applied/): Six inbound conversations, zero applications, and why the approach was worth it regardless of the outcome. (2026-07-27; raw markdown at https://jcosta.tech/writing/the-job-search-where-i-never-applied/index.md)
- [The AI Says It's Done. Make It Prove It.](https://jcosta.tech/writing/the-ai-says-its-done/): Coding agents get lazy on long jobs: they do the fun part and round up to done. A deterministic state machine takes that call away from the model. (2026-07-21; raw markdown at https://jcosta.tech/writing/the-ai-says-its-done/index.md)
- [What I Built with Claude Fable 5](https://jcosta.tech/writing/what-i-built-with-claude-fable-5/): An audit of everything I own, a dictation app, and the division of labor that stuck (2026-07-07; raw markdown at https://jcosta.tech/writing/what-i-built-with-claude-fable-5/index.md)
- [Your AI Setup Is a Depreciating Asset](https://jcosta.tech/writing/ai-setup-depreciating-asset/): The durable skill isn't building a better workflow. It's being willing to throw yours away. (2026-06-24; raw markdown at https://jcosta.tech/writing/ai-setup-depreciating-asset/index.md)
- [How I Give Claude Code a Persistent Brain in Obsidian](https://jcosta.tech/writing/how-i-give-claude-code-a-persistent-brain-in-obsidian/): Project state lives in your notes, the vault writes itself as you work, and it backs itself up offsite. (2026-06-17; raw markdown at https://jcosta.tech/writing/how-i-give-claude-code-a-persistent-brain-in-obsidian/index.md)
- [I Turned an Old MacBook Pro Into an Always-On Claude](https://jcosta.tech/writing/always-on-claude-home-lab-node/): A 2019 MacBook Pro, a Claude Max subscription, and a few open tools got me my own always-on, remote Claude without paying per token (2026-06-08; raw markdown at https://jcosta.tech/writing/always-on-claude-home-lab-node/index.md)
- [If Your Decisions Live in DMs, You Don't Have an AI Strategy](https://jcosta.tech/writing/if-your-decisions-live-in-dms/): The communication substrate every AI tool will run on (2026-05-14; raw markdown at https://jcosta.tech/writing/if-your-decisions-live-in-dms/index.md)
- [Not Every Business Win Is a Feature](https://jcosta.tech/writing/not-every-business-win-is-a-feature/): Where engineering value lives at a mature B2B company (2026-04-27; raw markdown at https://jcosta.tech/writing/not-every-business-win-is-a-feature/index.md)
- [Your Team Needs a Code Review Canon](https://jcosta.tech/writing/code-review-canon/): On shared standards, accountable review, and what AI changes about both (2026-04-21; raw markdown at https://jcosta.tech/writing/code-review-canon/index.md)
- [100 Merged PRs: What I Learned Contributing to Open Source with AI](https://jcosta.tech/writing/100-merged-prs-what-i-learned-contributing-to-open-source-with-ai/): On persistence, ownership, and shipping code in languages I don't know (2026-04-15; raw markdown at https://jcosta.tech/writing/100-merged-prs-what-i-learned-contributing-to-open-source-with-ai/index.md)
- [From Raspberry Pi to 17-Container Homelab in Six Months](https://jcosta.tech/writing/from-raspberry-pi-to-17-container-homelab/): Replacing streaming subscriptions with a self-hosted media server, book library, and monitoring stack, built in a weekend (2026-04-12; raw markdown at https://jcosta.tech/writing/from-raspberry-pi-to-17-container-homelab/index.md)
- [You Were Never Typing Code](https://jcosta.tech/writing/you-were-never-typing-code/): The job was never typing. It was choosing the right pattern and reviewing what ships. (2026-04-12; raw markdown at https://jcosta.tech/writing/you-were-never-typing-code/index.md)
- [AI Is Bringing Developers Back to the Terminal. Ink Is Making It Beautiful.](https://jcosta.tech/writing/ai-is-bringing-developers-back-to-the-terminal-ink-is-making-it-beautiful/): How a 36K-star React renderer quietly powers your favorite CLI tools (2026-04-07; raw markdown at https://jcosta.tech/writing/ai-is-bringing-developers-back-to-the-terminal-ink-is-making-it-beautiful/index.md)
- [Building a Self-Improving Trading System With AI](https://jcosta.tech/writing/building-a-self-improving-trading-system-with-ai/): An AI agent that reviews its own performance, runs experiments, and deploys improvements. Autonomously. (2026-03-31; raw markdown at https://jcosta.tech/writing/building-a-self-improving-trading-system-with-ai/index.md)
- [Automate Your Life With Cron Jobs, GitHub Actions, and Telegram](https://jcosta.tech/writing/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 (2026-03-26; raw markdown at https://jcosta.tech/writing/automate-your-life-with-cron-jobs-github-actions-and-telegram/index.md)
- [Your Portfolio Site Deserves a Pipeline](https://jcosta.tech/writing/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. (2026-03-15; raw markdown at https://jcosta.tech/writing/your-portfolio-site-deserves-a-pipeline/index.md)
- [Claude Code Tips and Tricks](https://jcosta.tech/writing/claude-code-tips-and-tricks/): For AI-Assisted Engineering (2026-03-08; raw markdown at https://jcosta.tech/writing/claude-code-tips-and-tricks/index.md)
- [The Biggest Bottleneck in Enterprise Software Isn't Technical](https://jcosta.tech/writing/the-coordination-tax/): The Coordination Tax (2026-03-05; raw markdown at https://jcosta.tech/writing/the-coordination-tax/index.md)
- [Why Functional Programming Is the Most Important Skill for the AI Era](https://jcosta.tech/writing/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 (2026-02-24; raw markdown at https://jcosta.tech/writing/why-functional-programming-is-the-most-important-skill-for-the-ai-era/index.md)
- [How to Have a Career in 2026](https://jcosta.tech/writing/how-to-have-a-career-in-2026/): A step-by-step guide for leveraging AI in any job function (2026-02-14; raw markdown at https://jcosta.tech/writing/how-to-have-a-career-in-2026/index.md)
- [What It Takes to Be a Software Engineer in 2026](https://jcosta.tech/writing/what-it-takes-to-be-a-software-engineer-in-2026/): AI made implementation easier. Here's how to stay valuable. (2026-01-27; raw markdown at https://jcosta.tech/writing/what-it-takes-to-be-a-software-engineer-in-2026/index.md)
- [AI Drives, You Direct](https://jcosta.tech/writing/ai-drives-you-direct/): How I finally started getting PRs merged (2026-01-20; raw markdown at https://jcosta.tech/writing/ai-drives-you-direct/index.md)
- [Why AI-Assisted Development Feels Like Engineering Management](https://jcosta.tech/writing/why-ai-assisted-development-feels-like-engineering-management/): How years of code review prepared me for working with Claude (2026-01-06; raw markdown at https://jcosta.tech/writing/why-ai-assisted-development-feels-like-engineering-management/index.md)
- [AI-Assisted Home Automation in 2026](https://jcosta.tech/writing/ai-assisted-home-automation-in-2026/): With Home Assistant and Claude Code (2026-01-03; raw markdown at https://jcosta.tech/writing/ai-assisted-home-automation-in-2026/index.md)
- [Modeling React State as a Finite State Machine](https://jcosta.tech/writing/modeling-react-state-as-a-finite-state-machine/): A modern approach using TypeScript discriminated unions and hooks (2025-12-30; raw markdown at https://jcosta.tech/writing/modeling-react-state-as-a-finite-state-machine/index.md)

## Key pages

- [Home](https://jcosta.tech/): bio, live OSS stats, recent merged PRs, selected writing
- [Writing index](https://jcosta.tech/writing.html): all posts
- [Open source contributions](https://jcosta.tech/contributions.html): every merged PR with repo, stars, language
- [About](https://jcosta.tech/about.html)
- [Testimonials](https://jcosta.tech/testimonials.html)
- [Contact](https://jcosta.tech/contact.html): consulting, advisory engagements, open source collaboration
- [RSS feed](https://jcosta.tech/feed.xml)