Phone Screen:
Implement a data structure to store key-value entries within a time-based interval.
Slight variation to LRU Cache.

Round 1:
Implement a Word Search Engine, given a list of documents with text, return the document ids that the given word belongs in. Followup: Search a phrase

Round 2:
Design TinyURL

Round 3:
Implement the Unix Tail -N Command

Round 4:
Talk about a project you had the most impact on, what was the biggest challenge, etc.