About
Six Fathoms.
My workshop — the place where the software and tools I build outside of work live. Not a company, not a product, not a pitch.
I'm Theo Zourzouvillys. I work full-time on the architecture and implementation of complex distributed systems in identity, security, and anti-fraud. Away from the day job I live aboard a sailboat in the remote waters of British Columbia and Alaska, and I keep a steady pile of side projects going. Six Fathoms is where I collect them.
I've spent decades building real systems at scale: launching products, scaling platforms, rebuilding infrastructure mid-flight, and recovering from the kind of failures that make for good stories afterward. After all that, the thing I still love most is the work itself — sitting with a hard problem and shipping something clean.
Why "Six Fathoms"
Thirty-six feet down.
Six fathoms is 36 feet. It's the classic depth where ships start to lose sight of the bottom, and where shallow solutions stop working. That's where I like to operate — not skimming the surface, but down in the depth where clarity matters, decisions have weight, and experience shows. It's also, fittingly, a number that means something when you live on the water.
Run from a boat
The office is off-grid.
My office is on the water. That setting shapes the software: when the nearest help is a long way off, you build for resilience and self-reliance by default. Things have to keep working without a network, without a datacenter, and without anyone to call.
What I work on
- Marine & boat software — charting, AIS, NMEA, and off-grid tooling.
- Security — signing, authentication, and protocols that fail closed.
- Big data — moving and processing large datasets efficiently.
- Distributed systems — correct, observable, unglamorous plumbing.
- High-performance SaaS — keeping services fast as they scale.
What I value
- Substance over spin. No theater. Do the real work and do it well.
- Experience that earns trust. I've seen what breaks and built what lasts.
- Small and focused. One person, a few projects at a time, done properly.
- Kindness and clarity. No egos. No assholes.
Want the personal story behind all this? It's over at zrz.io.