I was asked this question: https://leetcode.com/discuss/interview-question/483660/google-phone-currency-conversion
Similar to: https://www.careercup.com/question?id=5631096870928384 or https://stackoverflow.com/questions/3372375/algorithm-to-determine-exchange-rate

The interviewer was very nice and pleasant, he honestly gave me a of of tips -- unfortunately, I was not ready for a graph question. It seems that Flatiron Health really likes asking graph related questions (search on Glasdoor, they ask cities, number of islands, hexagonal titles, etc), so be be prepared to know how to traverse a graph.