See the reason ops thing works is this can even be applied to something you haven't worked on but purely as a passion project on the side. If you are Saying "oh what if I don't have side projects" you do realize people spend/waste 3+ months going these interviews + tons of mock interviews with companies they have no intention of joining. What does it say about if you are telling me you'd rather waste valuable personal time that way instead of building something fun?
I'm fact I'd even say that even if you haven't built a side project, I'd still use op's technique and ask the candidate to talk about and white board a system they would like to build and then dive deeper from there. Heck I'd even tell this to them before an interview!
I put in 60 hour weeks at my current job, except for a month before I change jobs, where I put in an additional 2 hours/night to prep for interviews, because that’s what will benefit me for every other company.
I care about my career and my family, so I don’t have the luxury of spending it on passion projects outside of work. I’d rather spend the precious little time I have left on my real hobbies and family/friends.
It doesn’t communicate that I’m a bad engineer. On the contrary it communicates that I give my all at work.
But I never said you had to spend all your life on passion projects. How is leet code fair game but asking how they would build something they would to even if they never did or do somehow an indication that I think you are a bad engineer? Because I see today's state of system design question interviewing pretty much like leetcode no (asking this as a faang interviewer)?
Having said that what you said about spending 60 hours at work tells others you will be a much better employee. Which is probably the signal they are looking for?
I am not going make judgement on people's loyalty. If someone chooses to do 60 hours works more power to them. If people don't want to do side projects that is perfectly fine too. Seriously my motivation wasn't to suggest id penalize those without a side project. It was more from my observation that (from several l5-l7 candidates):
1. Despite the "let us work together" intent it is still an exam where you are penalized for taking too long or making a "wrong" assumption or missing a few bits,
2. Given above or not when confronted with a random question it can be easy to get very nervous unless you have built a similar system from 1 to 1b user scale or you have done tons of practise interviews with companies.
So apart from interviews being hard and what they are purely because of supply and demand I wanted to see if you can learn just as much from a more open book approach (with either a side project or candidate knowing the question ahead of time say the night before). It could even be more inclusive that way!
I'm fact I'd even say that even if you haven't built a side project, I'd still use op's technique and ask the candidate to talk about and white board a system they would like to build and then dive deeper from there. Heck I'd even tell this to them before an interview!