I first received an email about my candidacy for an internship position over the summer. I then scheduled a quick phone interview to learn more about the internship program, discuss potential roles, and confirm my willingness to work in Seattle.

About a week later, I had a 45-minute coding interview over the phone. The problem was to write a function to remove elements in an array that appear more than once, which was somewhat algorithmically interesting yet fairly straightforward.

Later that day, I received an email stating that the feedback was positive and that I would have a final round interview. This round consisted of two 45-minute coding interviews and a short conversation with a hiring manager. I opted to do the interview onsite, as this was an option.

The onsite interview was a bit disorganized, as the company had recently moved into a new space.

The first 45-minute interview involved tackling the problem of finding the top 1000 most frequent words in a file with better than O(nlogn) complexity. I provided various solutions with O(nlogn) complexity before attempting to use min/max heaps. I was also asked to explain Quicksort and Mergesort, analyzing their complexities and explaining why they are O(nlogn), rather than just reciting from memory.

The second 45-minute interview involved developing and coding an efficient algorithm to find the "just less than" number in an unbalanced binary tree. This meant finding the largest number in the tree that was less than some target number, which was fairly straightforward.

Both interviewers were very nice. Afterward, I spoke with the hiring manager, who answered some of my questions.

I received an email the next day stating that they were moving forward with stronger candidates.

Find the top 1000 most frequent words in a text file with better than O(n log n) complexity. This is a tree traversal problem.