From 12 to 14 June 2026, Techstars Startup Weekend Valencia brought founders, developers, designers and students to Las Naves for 54 hours: pitch an idea, form a team, build it and present it to a jury. HUBBLR sponsored the weekend, and our co-founder Cedric Bals mentored the teams.
The same mistakes, including our own
HUBBLR has seen many startups make the same mistakes. As young founders we made some of them ourselves. We say that openly, because mentors who will not admit their own mistakes set unrealistic expectations for the founders they are supposed to help.
The FAST trap
Almost every early founder falls into what we call the FAST trap:
Fall in love with the product before talking to a single customer.
Assume the problem is real without proving it.
Skip selling until the product feels finished.
Treat the team as an afterthought.
What to do differently, starting today
Talk to lots of customers before you write a single line of code.
Validate with structured hypothesis tests: write down what has to be true, then test it.
Sell before you are ready. You will never feel ready.
Choose your founding team carefully, and treat it as one of your most important tasks.
The most unexpected moment
A young volunteer at the event is on a mission to fight loneliness among teenagers. That kind of drive at that age reminded us exactly why we show up for weekends like this one.
What is the biggest mistake you made as an early founder, or the one you wish someone had warned you about?
Language
