Where do you find study material for system design interview problems? I’ve tried to watch YouTube but it’s kind of boring.
I read Grokking the system design interview. It's not worth the $79. Many of the solutions are not described well or in detail. I bought it from eBay for about 30 bucks. If you want to improve your system design skills, read designing data intensive applications and building microservices.
Try to solve system design problems from below link - https://www.interviewbit.com/courses/system-design/
Grokking the system design interview on educative.io
Is there a free one?
Nope! Spend $79 to get a salary of $350k I was asked system design question as is in FB interview. This does give a fair idea on how to approach these kind of questions.