About Valentin De Matos
Valentin De Matos is a Paris-based AI builder and former founder who goes by Thytu on GitHub. He created OpenRostrum, an open-source alternative to the event and speaker management SaaS Sessionboard, covering CFP forms, speaker portals, submission review, agenda building and speaker communications.
OpenRostrum won the $10,000 top prize in Kill My SaaS, a challenge run by swyx of Latent Space and AI Engineer. AI Engineer had been quoted $43,000 a year for Sessionboard and asked builders to replace it with coding agents. The non-technical events team judged the entries, and they chose OpenRostrum for its multiple portals and a schedule they actually wanted to use. swyx said AI Engineer's 2027 conferences will probably run on a mix of OpenRostrum and the runner-up, Conferencer. OpenRostrum ranked only 19th on the challenge's automated AI judge.
He also writes about agent engineering on his blog, with posts such as "Harness Engineering 101".
Career Highlights
- Winner of the Latent Space / AI Engineer Kill My SaaS challenge ($10,000 prize)
- Creator of OpenRostrum, an open-source Sessionboard alternative
- Former founder
Notable Positions
On Guardrails Before Code
Valentin put most of his effort into guardrails such as code reviews and other checks, and made them into a GitHub template he reuses for every new repository so he doesn't have to set it up again. He explained the motivation: "I hate slop, like everyone. And if you have to take over this project, you want to be able to write on it." Before planning, he had Codex map every flow of every feature from the product's help content and YouTube videos into folders of markdown specs. He then split the work into what agents could build at the same time and what had to happen in order.
On the Five-Minute Test
His quality bar was simple: "if I have only five minutes to test the product, what will it be?" If the five minutes weren't smooth, he didn't patch the result by hand. He reran the process and asked the agent to read its own traces to find the missing context. In one case the spec had a title for onboarding but no definition of good onboarding, so he added a research step to the agents' workflow.
Key Quotes
- "In many projects, I have to redo this whole work." (on turning his guardrails into a GitHub template)
- "As long as the five minutes were not smooth, I would redo the whole process." (on dogfooding agent-built software)
Related Reading
- Kill My SaaS: Replacing a $43K Sessionboard with AI Agents - The challenge he won
- Software Factory - The approach swyx credited in OpenRostrum
- SaaS-to-AI Transformation - The broader shift behind replacing SaaS