Ownership of IP is covered by law and precedent. You should research that. Everything in an employment contract is negotiable. You can expect all employers to assert ownership of IP developed as part of your job, or on company time, using employer-provided resources, or within the scope of your assigned work. Anything else you can negotiate.
Good luck getting a job at a FAANG company grinding on leetcode to make a big salary so you can work on a side project. They love people aligned like that with their goals.
Good luck getting a job at a FAANG company grinding on leetcode to make a big salary so you can work on a side project. They love people aligned like that with their goals.