José Miguel Hernandez

I build applied AI and the agent platforms other engineers ship on.

I'm a Staff Software Engineer in applied AI and agent platforms. I build agents, the guardrails that make them safe to run, and the tooling other engineers build on. I came up through design and frontend engineering, across social media, music and advertising, so I tend to work on both the interface someone touches and the platform underneath it.

I spent nine years at AdRoll. All nine, I worked on the component library 28 repositories depended on. I rebuilt the ad builder, and by fall 2025 about 250 advertisers were spending on ads built with it. In the last stretch I brought LLM agents into how our engineers work and into our design system. Before AdRoll, three of my companies were acquired, and I moved with the team each time.

github.com/jose-m-hernandez
7,035 contributions on GitHub in the last 46 weeks
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Morro Bay, California · remote

Background

Engineering roles across advertising, social products, games, and streaming media.

  1. AdRollStaff Software Engineer2017–2026Senior to Staff · Applied AI, Platform
  2. PandoraSenior Software Engineer, Consumer Electronics2015–2017Consumer Electronics, Chromecast
  3. RdioSenior Software Engineer2014–2015Partner Platforms, Device Runtimesacq. by Pandora, $75M
  4. TastemakerXSenior Software Engineer2013–2014Relaunch, Music Discoveryacq. by Rdio
  5. TellyLead Front-End Engineer2011–2012Social Video, Onboarding
  6. 50 CubesDirector of Activation2010–2011Social Platforms, Payments
  7. AOLSenior Software Engineer2008–2009Ad Tooling, Messaging
  8. BeboSenior Software Engineer, Ad Operations2006–2008Sponsorships, Ad Systemsacq. by AOL, $850M

Education

  1. UC Santa CruzFilm and Digital Media

Projects

  1. cleanroom-researcherRepeatable experiments on AI tools. Each writes down its question, its method and the result that would count against its prediction before the first run. Once one has run, a single command rebuilds its tables from the recorded data. The first two test a Claude Code memory plugin.
  2. career-track-recordFour checks for the career copy you send: a barred-wording check, a job-posting keyword scan, a voice and tone check, and Reader A/B, which compares two drafts with test readers under a plan frozen before the first read. A test fails if any tool imports a network or mail library.
  3. KidzoneMy kids and their friends design browser games here with an AI coding agent. They bring the idea, the agent builds a rough first draft, and we play it and refine it together. Built with dezi-bot; a CI check holds every game to its privacy rules.
  4. SuperkidsA points app for families. Kids earn credits, and both parents track the same list from their own phones. I rebuilt it as a multi-family Next.js and Supabase app with magic-link sign-in, where row-level security keeps each family's data apart.
  5. XTreeJSAn homage to XTreeGold, the DOS file manager from the company my father co-founded. I vibe-coded it one night for fun, to see how far I could get: a terminal app in TypeScript on Bun that shipped with tests and CI.