Meta Intern interview questions

A telephonic interview was scheduled. The interviewer asked a coding question. No language barrier was there. One coding question was asked. The question was of difficult level. The interviewer was not giving any hints for the same.

Interviewed for Instagram's Facebook University Internship and was flown out to their headquarters for the interview. There was an orientation about Facebook/Instagram and a presentation from the head of engineering. Then, me and 13 others broke off with separate interviewers and we each had 2 30 minute sessions with 2 different interviewers.