I was referred by a friend.

I interviewed at London, UK. The process took nearly 4 weeks.

Round 1: CoderPad interview: 2 questions that I solved in 40 minutes. They were not so hard, involving greedy algorithms and mathematical puzzles.

Round 2: On-site round 1: Problem-solving with data structures, specifically Binary Search Trees and HashMaps.

Round 3: On-site round 2: Problem-solving that could be formulated as finding the number of connected components in a graph (so using DFS) and sorting.

Round 4: On-site round 3: Problem-solving related to databases, including a Hadoop-style question.

Round 5: On-site round 4: System design, involving designing a system to support reviewing and sending documents, and how to scale it.

Round 6: On-site round 5: Behavioural questions, such as how to deal with deadlines and discussing motivation.

Which data structure would you use to formulate a collection of (user, threshold stock price) so that you can alert the user whenever a stock price in the market goes below (or above) the threshold value?