Coding challenge: about a dozen miscellaneous CS questions (e.g. on what data structure would you run binary search, a sorted array or linked list, what's the base-10 value of the largest 32-bit unsigned integer). This was followed by: given a list of restaurant ID-rating pairs, sorted the pairs by rating. 1st round: implement a mini "search engine." I forget the details, but it was basically associating basic user queries with restaurants whose names/descriptions matched that query. 2nd round: questions on concurrency and thread safety, and then "flattening a dictionary" e.g. given {a: 1, b: {c: 1}}, output {a: 1, b.c = 1}. Next interview was a lot of questions about garbage collection and then given an array of strings, group together the strings that are anagrams of each other.