Meta Software Developer interview questions

I was contacted by a Facebook recruiter, and offered an interview for a Software Engineer Internship. I had two interviews, both a combination of talking on the phone and coding on collabedit.com. The first interview took place about five days after I was first contacted about the position; the interviewer asked a few questions about projects I'd done and then started with programming questions. The second interview happened a week later, and the interviewer dove straight into coding problems. I was asked general algorithm questions, like get the n-th Fibonacci number, find the square root of a number, find the depth of a binary tree, merge two arrays, etc. Both interviewers saved time at the end for any questions I wanted to ask them.

I was hiring specifically for an iOS position. The recruiters start with Obj-C 5 multiple choice questions, which required some surprising depth. I won't get into specifics, but take time to understand memory management (even with arc), blocks, addresses and pointers. After was a phone interview which mostly involved a collaborative coding question. The questions asked here were very typical algorithmic questions, the answers usually involved a hash to cache meta values to increase performance. Protip: Be familiar with NSSet and NSOrderedSet. These data structures are more performant than NSArrays for some operations, and I found myself using them in almost every answer. Then you have an onsite visit, with 4 additional interviews: 2 coding, 1 design, and 1 "culture fit" which, for me, was really another coding interview. Your recruiter will contact during the next week or two afterwards to give you updates on your status. I believe there are three different meetings where your interviewing notes are reviewed and given consideration.