Yeah, as a Portuguese person living in Lisbon and having worked in the tech scene here, I can say avoid Portugal if you're looking for a SV type scene. The level of anything going on around here is far lower.

Sure the weather is the best I've ever experienced on earth, the food is great, and the cost of living is low. But on the other hand you have an ecosystem that is nothing to write home about, culturally it's good but not great like London or NYC, academia is lackluster (no world-class universities in any subject, bar 1 MBA), not very international, not a whole lot going on in general.

Portugal is a great place to come on holiday, go surfing, go sailing, and retire. It's not an intellectually stimulating place, and the general level of competence in everything from local government to enterprise management is extremely frustrating.

I would say to OP that usually if a place is interesting, it won't be cheap as there is more demand for it. Maybe look at Oxford, UK, Bristol, UK, Edinburgh, UK, or Rotterdam, NL as secondary cities with still enough going on. Apparently Bordeaux is nice but I have never been so can't say.