If you are interrested by this problem Trainline is hiring and my team is working on connecting the Train carrier API to a single backend like what you have in the airline world.
Parent company Illiad is a big french telecom operator. They have their own datacenters, big network connectivity and already big deals with hardware manufacturers.
They are know for cutting the cost by running project with very small and smart team with hacker culture.
And after the trial period you can't easily be fire (usually in startup you just negotiate sometimes to move and found a new job). And if the company die your missing salary will be paid by the state.
They need warrant to get access to your server. What they can do is to collect metadata in some points of the network, they don't need amazon to do that, because they target end users.
But it's probably not a good idea to host in France if you have not reason to do that. Like NSA, french secret service just don't care about laws. But if you target french customer that's good news you have one more alternative for hosting without trouble with regulation about data.