Your intuition is correct, you really should try to make sure your employer is aware of your intent to work on your own IP and you have some written document ac

Your intuition is correct, you really should try to make sure your employer is aware of your intent to work on your own IP and you have some written document acknowledging that fact. Many companies have a form you fill out on your first day listing such projects. You owe your employer a duty of loyalty and so your projects cannot compete with them, and it helps to have them review the scope of the project and sign off on that fact. If you don't get this agreement from your employer, you might still technically be fine to work on your own business but you risk a court battle about it. > I’ve also read that these kinds of clauses can even apply several months after you terminate at your day job, which suggests that you can’t even start on the product until months after you’ve left. These would be non-compete clauses, illegal in California but legal in many other states. Your employer doesn't own any IP you create once they stop paying you, but if you are bound by a non-compete you'll need to be more careful.