An employee can be laid off if he agrees to it but that's not like firing because it needs an agreement. I am not sure if the OP is talking about that.
It's possible to fire people without justification and the company will be brought to court. There is a new law from Macron that caps the damages the employee can get to pretty much nothing when he only has a few years of tenure or less. You could provision for a few months of salary.
I can confirm that you can fire people in France at a reasonable cost if you know what you’re doing and are focused on paying good money for great people. If you’re looking to build a large-scale sweatshop of low-skill workers with low pay and high turnover... then sure, France is not the place to do that. But if you’re a typical tech company not afraid to pay above market for top talent... cost of severance will not be an issue.
(I’ve hired and run large engineering offices in France and in the US).
It's possible to fire people without justification and the company will be brought to court. There is a new law from Macron that caps the damages the employee can get to pretty much nothing when he only has a few years of tenure or less. You could provision for a few months of salary.