The issue with system design is that it doesn't always have a perfect answer and a lot of things are arbitrary about it. This leaves a lot of bias with the interviewers as to how to interpret the answer and question. This is less the case with Leetcode where there is usually only one or two optimal ways to solve a problem and you can just argue over time and space complexity as a means of what "optimal" is.
System design has a ton of bias in it and it's my least favorite type of interview because of it.
I guess at this point in my career the soft side of system design questions are a good thing. I'm interviewing the team as much as they're interviewing me. The inability to have a soft discussion about something like system design that shouldn't have one right answer is them failing.
System design has a ton of bias in it and it's my least favorite type of interview because of it.