Hello,I'm a software developer with 10-15 years of experience under my belt, but I spent most of them not working on technical problems challenging enough to justify the 10-15 years and only last 3-4 years I moved to backend. I sure as hell delivered quality software that paid the bills and then some.Needless to say that I'm quite rusty and/or unexperienced in most of the typical interviewing questions and I need to get up to speed but I work full time and I have no energy after 40 hours work week.I want to move land a job in FAANG type of company in the US and I know leetcode type interviews is very common there. My idea is to quit my current job so I can dedicate my time to studying for interviews. I can afford this since I will rely on unemployment money in my home country. 
Do you think this would be a waste of time? did anyone do such a thing? what are your thoughts fellow HNers?Thanks in advance!