Overall, Facebook's interview process was slow and uncoordinated.

I was referred but dealt with their internal recruiters throughout the process. After chatting with one recruiter, I was told they'd schedule an initial screening interview. Since I was local, this was done at their headquarters instead of over the phone. This screening actually consisted of three one-on-one interviews and took over two hours. The questions were pretty basic, and none were too difficult.

I passed the screen and went back for another round of one-on-one interviews. These questions were tougher. One was about scaling an app I'd written to Facebook scale. Since I don't have a ton of experience working at scale, I'm unsure if I flubbed it. Another question involved processing log files of events to determine a user's current status. The final question was about splitting strings using a dictionary (search for "Retiring a Great Interview Problem" if you want the details), which I eventually worked through.

After that, I was asked back for a third round of one-on-one interviews. I was told this one would be quick, but it was just as long as the others. Most of the questions were actually about work I'd done previously and data visualization.

After this, I received a call from a recruiter who sounded excited, saying they were going to do a background check and that I should expect to hear back when the hiring manager returned from vacation. However, that time came and went, and I was eventually told (via email) that the position had been filled, so I didn't receive an offer.

I'd like to draw special attention to how slow this process was. After my initial contact with a recruiter, it took two weeks to schedule and conduct the screening interview. It took another two weeks for them to get feedback and schedule a second round. After the second round, it took another three weeks to schedule the third round. Then, it was another two weeks before I heard back. I had nearly wide-open availability, so the only thing holding things up was Facebook.

I'd also like to draw attention to how uncoordinated the recruiters were. My initial contact was with one recruiter. After chatting with him, he handed me off to a second recruiter. She scheduled the second interview, after which I was handed off to a third recruiter. After that, the email stating the position had been filled came from a fourth recruiter. Meanwhile, the recruiters who helped escort me around on site during the interviews were different from any of these. It was very difficult to keep track of who to contact with questions, updates, and thank yous. I also think the job title I was applying for changed at least once during this process, which led to some confusion in the interviews, though all recruiters involved assured me it was the same position.

More uncoordination: they asked me to fill out an application form, and I did so and turned it in at my screening interview. They then asked for this same form at every subsequent interview, and even once over email. I had to keep reminding them I'd already completed it.

Also, just a gripe. All three of my on-site interviews were scheduled to begin in the morning, and they all lasted well past noon. I was only offered lunch once.

They asked how I'd scale a web app, which I'd previously developed in my spare time, up to Facebook scale.