I have reached a point where I am comfortable enough with implementing things that I do not need to practice as long as I understand how it works. So I get to s

I have reached a point where I am comfortable enough with implementing things that I do not need to practice as long as I understand how it works. So I get to spend all my free time on side projects just like you. I have a set of downloaded algorithm lectures by Robert Sedgwick from Coursera (text version: http://algs4.cs.princeton.edu/home/ http://algs4.cs.princeton.edu/home/) that I watch before every interview. I make it a point to do this even if I think I remember it well. In fact, I now know parts of the course so well, that I can watch it as 2x speed in VLC, and that refreshes everything in my mind. To be fair, I'm still in college, and all my interviews were for internship positions and algorithms focussed, so it might definitely differ from your situation. However, what I learnt from this set of videos has never failed me with any of the big companies. PS: I use scripts like these (https://github.com/coursera-dl/coursera https://github.com/coursera-dl/coursera) to download useful courses from Coursera that I can then watch before interviews.