After submitting my resume and answering a few questions on past projects, job preferences, etc., I had two Skype interviews focusing on algorithmic questions. The problems posed were quite fair and had to be solved in a programming language of choice within an online editor.

After that, I was invited to an on-site interview in London (expenses paid) with three more one-on-one sessions. Two of these focused on coding, this time on a whiteboard. The other session also included a small coding part but also covered questions on previous projects, team behavior, etc.

Why do you want to work at Facebook?