Teo Ruiz

I’m a software engineer and entrepreneur. I generally like learning how things work.

I’m a Co-Founder at Vernon, we help tech companies build software and digital products.


Over the past ~20 years I’ve been lucky enough to work on great projects and with great people:

  • I co-maintained a Debian-based distribution (while being an official Debian maintainer).
  • I was the first employee, founding member of the engineering team and VP of Engineering at FON.
  • I managed the web development team at El País, one of the biggest newspapers in Spain.
  • I’ve been CTO at Busuu, the biggest language learning startup in the world by number of users.
  • I’ve headed the great engineering team at Lyst in London.
  • I was VP of Engineering at Jobandtalent.
  • For five years I was a Co-Founder at Circular. We tried fixing the recruiting problem for candidate-driven industries, starting with tech and product recruiting for startups. We sold the company to Sngular in 2024.

You can see my full CV and contact me on LinkedIn.


In tech I like free software (free as in free speech), DevOps, systems and infrastructure engineering (especially on AWS and GCP), scalability, databases, automation, coding for fun and profit, the startup scene, and in general being geeky about technical things.

In Real Life I like music, music, music and then some other stuff (randomly sorted, ridiculously non-comprehensive list): writing, travelling, politics, quality alcoholic beverages, coffee, hanging out with my friends, food, photography, economics, reading, movies and running.

Languages and writing

Spanish is my mother tongue but I have a crush for the English language so some of the posts on this old blog were written (some would say committed) in that language. Please bear with me.

Python is my preferred languages for everything else, although I’ve had the doubtful pleasure of working with PHP for a few years. The Go language has recently gone to the top in my toolbox ranking and I try to use it for new projects.