Dropbox asks difficult questions, and it's hard to discern why. I don't believe the problems at Dropbox are particularly difficult relative to its peers. I don't think they innovate at a clip that's outsized, etc.. But they do this, and their engineering culture focuses on this.
That said, I think what I noticed at Dropbox is that asking lots of tough questions gets you a lot of pretty talented folks who are very interested in solving hard technical problems. So from an infrastructure side, Dropbox was overflowing with talented people. From the product side, though, it was harder for teams to staff frontend projects or make progress when their ideas were challenged by infra.
Startups ask questions 80% of engineers can answer because they don't have many applicants. Dropbox might have 50 decent applicants who could all probably do the job for every opening. How do you decide who gets it? Ask an easier question and you end up with way more passes than you have openings.
My point is Dropbox asks questions that are beyond what its peers ask, even companies not its peer (FAANG, which we don't think Dropbox is apart of).
This is an explicit decision by the engineering leaders at Dropbox. It's interesting, and I'm wondering if it works for them.