Super tough tech screen. Be prepared. I was reached out by a recruiter. Had phone call and schedule tech screen. Interviewer was nice but they really don’t go over your background or about you in the call. Just straight to the code so expect that. The problems were as follows: Given String word and a string order sort it according to the order. So given ABBCC and order CBA the result should be CCBBA. I used a HashMultiset of Character and iterated over input. Then I iterated over the order and added the count from the set of that character, not too difficult. Second problem was to do columns of binary tree and the columns should also be in top down order. Final result is list of the nodes data in that order. Honestly no clue how to solve that. I tried doing a traversal and fit each node putting its row and column into a map and then finally building up the list by sorting on the column