The successful ones are now Parrot and Criteo. Remember those? But there are plenty of small startups that are doing challenging stuff. Interested in machine learning? Check out mipsology.com
If you want to be paid well, you need to work for a company where the technology is the product. Writing Java for a bank? The software is not the product, so you won't be respected like in Silicon Valley.
I don't know why but from my experience there is many PME woking as startups in the south west of Paris specially in embedded dev and video. Maybe for web dev they are more located "intra-muros".