I approached DoorDash at a university career fair and heard back from the recruiter about a week later.

The coding challenge was sent a few days later.

The next round was a two-hour Zoom interview, with back-to-back CoderPad problems. The first interviewer was more engaged, while the second interviewer seemed less interested in offering help or advice and stayed pretty quiet throughout the whole hour.

The last interview round was 1.5 hours. The first hour involved another CoderPad exercise, followed by a 30-minute behavioral interview. I must have answered each of the questions too quickly because I was asked a lot of behavioral questions.

Game of Connect Four.

Given a piece, check if any player has won the game.