Presumably they raised money, and will need to raise money again. That means that they have money (it's worthwhile to sue, assuming you can get damages). It als

Presumably they raised money, and will need to raise money again. That means that they have money (it's worthwhile to sue, assuming you can get damages). It also means it's a huge lever: they'll never be able to raise under active litigation, they'll have to tell their board, etc. Now is the time to do this. If they just pivoted, and are literally copying you, they can just pivot to something else. You could even get them to agree to transfer/refer their customers as a settlement. All this assumes they did something illegal. Copyright is the best thing to check: have they literally copied anything (APIs may be legal to copy, see Oracle vs Google).