I applied through a career fair in college and was called for an on-campus interview.

After two weeks, the interviewer notified me to go for an on-site interview. I chose San Francisco, at Facebook's headquarters.

The first question was easy; you only had to DFS or BFS to find all adjacent areas.

The second question took place at the on-site, and it was a little bit harder than the first one.

Given a 2D matrix where each cell contains a character from the alphabet, verify if a given word exists in this matrix. A word is considered to exist in a matrix if there is a path from cell to cell in the matrix that creates a word matching the word we're looking for. A cell can move to all vertex-adjacent cells (so there are 8 adjacent cells) and cannot be used more than once.