A recruiter from Niantic reached out to me on LinkedIn. I was scheduled to do a phone screen with an engineer from their San Francisco office. The interviewer was punctual, polite, patient, and answered all my questions about Niantic very precisely.

After introductions were made, I was asked about my background and presented with two "technical" questions.

One question was pure math (Statistics / Probabilities): it required calculating cumulative probabilities of a specific mechanic of one of Niantic's games. Before I could say anything, the interviewer eagerly explained that probabilities are important at Niantic because they help keep the game balanced. This felt as if the interviewer anticipated pushback and tried to justify asking this question preemptively.

The other question was slightly closer to computer science and is an exercise in which one is given a set of integers (the interviewer starts with 3 and asks not to generalize at first) and must select one matching certain conditions. It is required to perform this operation without using any of the language's standard library functions, causing the solution to become a laundry list of "if"s. I was offered to choose the language in which to write code.

Calculate the probability of a player successfully attaining a certain in-game goal after N tries, knowing the probability of one attempt. The statistic variable is independent, so cumulative probabilities can be used.