At a hiring event, you mingle, and if mutual interest is present, someone will put you on the interview list. A few days later, the intense, four-round interview process begins, with each round taking about an hour. After the second round, or in some cases after each round, they may eliminate you from consideration. You are only considered a potential hire if you make it to the end of all rounds.

The first interview is informal and serves multiple purposes. It helps you ease into the process and overcome the initial anxiety most people feel when arriving for an interview. Secondly, it's a cultural fitness check: are you the kind of person who fits into the company culture?

The following rounds are the professional interviews. These involve discussions of past experience, problem-solving exercises, system design, and writing code for both general and specific areas related to the role.

Some of the problems are difficult, but the goal is not for you to solve everything perfectly. While they want to see if you meet expectations, they are primarily looking for your problem-solving strategies, your strengths and weaknesses, and generally how you would perform on the job. For example, if you don't know something, you should still present your strategy for solving the problem. You might be allowed to do a Google search, but at a minimum, ask questions of the interviewer and proceed with the new information.

Design a whole TinyURL-type system (front end, back end, database, ...)