The way I see it you have two options: 1. Make what you're working on explicit and transparent in the contract you draw up with that startup. This has to be ma

The way I see it you have two options: 1. Make what you're working on explicit and transparent in the contract you draw up with that startup. This has to be made / checked by lawyer in order to avoid any ambiguity. 2. Don't work for the startup. If option #1 is worth it depends on how much profit you expect to make from the contract.