The Affirm Recruiter reached out and explained the process, which had 4 rounds: a 1-on-1 problem-solving round (generally a classic LeetCode style in a language of your choice), a hiring manager round, a systems design round, and a virtual onsite round with other senior team members.

The interviewer was nice and professional. She offered help whenever I got stuck in the 1-hour coding round. Although I was able to resolve the problem in the end, there wasn't enough time left for her to ask additional follow-up questions extending the problem.

It could depend on the level of the role you are interviewing for, but I suggest brushing up on your data structure basics instead of going into medium or hard LeetCode problems.

Implement a data structure that supports dictionary operations: get, put, and delete. It should also include a special operation, get_random_val, which returns a uniformly random value sampled from all the values in the dictionary. Each function should run in constant time, with the exception of delete, which for this part we relax to linear time.