Companies can easily workaround the 35 hours week with the "cadre" status that basically nullify the regulated hours constraint, and they do.
I don't know any developer in Paris that do a 35 hours week.
Actually it's even the contrary, French managers have a strong culture of evaluating employees performance based on presence. So you see a lot of peoples doing 10-12 hours a day, or coming back to the office on saturday.
This. I don't know any french developer not being on a day rate instead of an hour rate. An awful lot of people on an hour rate have a number of extra hours factored in their salary by default.
It's still better than the US, "cadre" status (but not top management) is officially around 180-190 day of work per year (depending on the unions).
I don't know any developer in Paris that do a 35 hours week. Actually it's even the contrary, French managers have a strong culture of evaluating employees performance based on presence. So you see a lot of peoples doing 10-12 hours a day, or coming back to the office on saturday.