After we worked on it for half a year the company ran out of money and stopped working with us. Some time later my friend continued working with them from time to time but I did not. Product gained some traction and 3 years later was sold to a very big company, basically and industry leader. Founders made a lot of money and my friend was asked to sign the release documents for this big company which he did. I was not asked and didn't sign anything. The big company turned out to be a little bit crazy over IP and non-solicitation and later sued the founders of our product over some bullshit, but this isn't related to my case. They killed the product development last year, immediately firing around 20 people working on it leaving only a couple of developers and a manager to support existing clients.
Anyway, the big company is still using the product based on the code I wrote (they still have my commits in their repository) and since I never signed away any intellectual property rights I believe I have a claim to IP in the product. I come from a country where litigation over IP is very uncommon and I have absolutely no idea how to proceed with this case. The big company is based in US, I'm currently in Europe. What are my options here? Is there any lawyer companies that specialize in cases like this and they can look into it?
I would appreciate any suggestions.