JC
Julissa Cotillo
engineer turned founder// AI systems

I'm Julissa. I build AI that earns its keep.

Engineer turned founder. I build production AI (agents, context engineering, and the isolated workspaces that keep them under control) for my own companies, and for any company that wants AI to actually work.

building in public, from Tampa

Build logs

Notes from the journey. Wins, fails, and the boring middle.

Moving off ___

How I migrated 3 open-source apps off a flaky VPS in one afternoon — and saved ~$80/mo doing it

How I migrated 3 open source apps off a flaky VPS in one afternoon and saved ~$80/mo doing it For months I’d been running three open source apps on a single Coolify VPS: Ghost for my blog, Rocket.Chat for agent notifications, and a Mastra based web scraper that occasionally went feral. It wasn’t catastrophic, just unreliable enough that Google Search Console started flagging 5xx crawl errors and UptimeRobot pinged me awake every few days. I even built a Cloudflare Worker watchdog that redeploy

May 22, 2026
Building in public

How Mastra's SF Demo Day Solidified My Bet on TypeScript for AI

How Mastra's SF Demo Day Solidified My Bet on TypeScript for AI I’ve been a software developer for over a decade, and for the past five months, I've been quietly working with Mastra, a framework I stumbled upon while searching for a seamless AI workflow management solution. I was already a fangirl, so when they announced a demo day in San Francisco, I knew I had to be there. I flew in with high expectations, and the event didn't just meet them—it blew them away. I walked out more convinced tha

Apr 21, 2026
Building in public

The Real Tech Stack Behind Our Airbnb: Price Labs, Cameras, and Why We Use Dumb Locks

When we launched Breezy Keys, our short-term rental business in Florida, everyone told us we needed the fanciest smart home tech. Smart locks, smart thermostats, automated everything. We tried some of it. Some stuck. Some we ditched. Here is what we actually use day to day, and why our setup is probably simpler than you would expect. Price Labs: The Biggest ROI in Our Stack If I had to pick one tool that has made us the most money, it is Price Labs. Dynamic pricing is not optional if you are

Mar 17, 2026

Have an AI problem worth solving?

Any company, any industry. If AI could move the needle for you, I'd love to hear about it. I read everything.