I have 9 hours a day to prepare for Full-Stack Developer interviews. How would you utilize them?

I can dedicate around 9 hours every day to interview preparation, and I'm targeting Full-Stack Developer (MERN) roles.

If you were in my position, how would you utilize those 9 hours each day to maximize your chances of cracking interviews? I'd really appreciate hearing how you'd structure your preparation and what you'd prioritize.