Unfortunately when it comes to preparing for interview leetcode is pretty much required at all stages. For that the way that works for me is to never let go of it. I will solve 2 3 problems over a week even when I have a job. That downtime at work when you are at home or waiting for the next meeting...just leetcode. I absolutely hate LC and hate the fact that it is omnipresent but now no longer fear it. Except Dynamic programming. That thing can go f*ck itself. But ya now when it comes to LC I am "always" or rather one week away from interview ready.