I applied through a staffing agency. The process took 1 week.

Had a decent conversation with their recruiter who sold the company aggressively on their Series D funding. Then had a technical call with one of their engineers who was honest and thoughtful.

Next is where everything went downhill. As some of the others have alluded to, they have a very bewildering way of reviewing your coding challenge. It is funny because they make a huge deal about how they abide by the principles in Clean Code, yet they will ding you for not using "preferred syntax" in your code. It makes you wonder if they even read Robert Martin's book?

If they truly cared about writing clean code, where is the emphasis on code organization and design? Or if best practices are being met? I suspect they have their junior developers doing these code reviews.

Don't waste your time with these folks. The feedback I received was simply laughable and certainly not things a senior/staff engineer would even bring up.

Given an integer array of zeros and ones, how would you move all the ones to the front and all the zeros to the back?