Interview stages:

• HR interview
• Phone interview with engineer
• Virtual onsite interview (5 sessions)

They have too many "gotchas" to learn, such as "culture," 14 principles, shareholder letters, the CEO's bio, a first dog in the office (who died years ago), and so on.

I practiced for weeks before the phone interview, and then I practiced for a few more weeks before the virtual onsite interview.

Phone Interview:

1. What data structure would you use to represent buildings and doors?
2. How would you find the shortest path from any room to an exit?

Virtual Onsite Interview:

1. Implement the Unix find utility as a library API.

   • Inputs: A starting folder and user-defined criteria to match. Let's start with: a) Name pattern b) Maximum size threshold
   • Output: A list of files matching the given criteria.
   • Looking for design of abstractions (inputs), implementation of the API itself, and sample usage.

2. Given a list of strings, determine if they are isomorphic and group them by isomorphism. Two strings X and Y are called isomorphic if all occurrences of each character in X can be replaced with another character to get Y, and vice-versa. Consider the strings “ACAB” and “XCXY”. They are isomorphic as we can map ‘A’ -> ‘X’, ‘B’ -> ‘Y’, and ‘C’ → ‘C’. Mapping from a character to itself is allowed, but two different characters may not be replaced by the same character.

3. Find the balance point of an array. Example: [3, -2, 0, 4, 6, -5] -> [3]

4. Behavioral questions (actual interviewer didn't show up).

5. Mobile System Design.