Yelp Software Developer interview questions

Interviewed at Yelp in Spring 2014. HR contacted initially and asked the regular screening questions found on glassdoor. Then she setup a phone interview with an engineer. Phone interview: pascal triangle anagram sort anagram sort for a huge list of words that won't fit in memory how to improve performance of websites in java, if two objects reference each other, then will they be garbage collected onsite interviews: had 4 interviews 1st: why yelp? some java questions will adding more indexes to a database improve performance? given a string, find longest string with unique characters 2nd: why yelp? given a list of urls, find top 10 most visited urls 3rd: why yelp? anagram sort implement the 'cd' command i.e. given a function cd('a/b','c/../d/e/../f'), where 1st param is current directory and 2nd param is the sequence of operations, find the final directory that the user will be in when the cd command is executed 4th: again why yelp implement regex It was not a super difficult interview but not an easy one either. In the end, I did not get the offer. But I did liked the interview process and would definitely like to work with them in the future.