I applied through the website.
It started with a 30 minute phone screen with a recruiter, going through mostly my background and why I was looking to move roles. Passing that led me to the next stage, which was comprised of a coding test (Hacker Rank) and hiring manager interview.
The coding test required one to write a CLI application to store and retrieve passwords in a secure way and was relatively simple if you had worked in any common programming language before. The interview with the hiring manager was pleasant, but it's definitely true they really want you to sign up and play their games prior to any later interviews (same as other have said). I was basically told by the recruiter that the if I were to get to the later interviews, that higher management would expect that I had signed up and played a certain amount of their games. Like other interviewees, I wonder if this is to pump up their user signup numbers.
After that, I had a call with the initial recruiter again to chat about next steps, which would involve a further 5-6 hours of interviews ("virtual onsite"). The steps would've included: chat with hiring manager (again), systems design (whiteboard an Instagram clone), chat with hiring manager's boss, chat with VP, etc. It sounded like I was going to progress to the next steps, but I ended up receiving a rejection before they scheduled any further calls.
I ended up being turned down for a reason that would've been apparent during the HR screen, so I'm not sure why they wasted time on further interviews and a coding test. Frankly, I wasn't very interested in moving forward with the lengthly process anyway, so it's probably for the better. In total, I counted about 8-10 hours (!) of interviews/tests total, which is kind of ridiculous for this position and company. Definitely make sure you absolutely want to work for them before applying.