There was an article on The Register[0] about something especially nutty Amazon Games Services required of employees, then later backed off on. (Cheers to them for caving to pressure.) Apart from that I've got no good references. I believe AWS typically put the "usual" overbearing clause in their contracts, where any IP you create before or during your employment becomes theirs. Sadly, so do many other employers. My previous employer did, and it was a sticking point for me and one reason for leaving.
[0] https://www.theregister.com/2021/08/13/amazon_game_contracts...