Contacted through LinkedIn and passed the phone screen. Went onsite for five interviews.

They asked me:

• Systems Design: What happens during and after a query is typed (autocomplete) in a search box, whether the user is trying to go to a website or asking a question. How do servers complete the request and what is the best (parallel) structure for the request to go through? DFS and how servers are located for proximity.
• Data Structures: What is the best data structure for a threaded email system? Linked List. Connecting and disconnecting links to update which email arrives in order by date and time.
• Data Handling: If you have data coming in rapid succession, what is the best way of dealing with redundant data? A queue and a hashmap.
• Recursion & Efficiency: I forgot this exactly, but it was about a binary tree with only two functions, getNumChildren() and getNthChild(n). The main point was to use recursion to [find duplicates or a certain node, perhaps]. Then we discussed spatial and memory efficiency (Big O).
• Text Search: The last one I forget, but it had to do with finding data in a large group of text. I should have used a hashmap. You could probably reason that a binary tree works because of space efficiency.

The search autocomplete question and how servers are distributed for maximum efficiency surprised me, as I spent my time doing programming questions and not reading up on conceptual design knowledge.