Arrays, Strings & Hash Maps

Wayfair's coding rounds are deliberately practical. You are working arrays, strings, hash maps, and the occasional stack, at a difficulty that sits mostly in the easy-to-medium band, with a hard problem showing up only on the timed online assessment. The prompts favor everyday data manipulation over obscure puzzles, and the bar is blunt: working code that passes every test case, with the time and space complexity you can state on request. Clever earns nothing here. Correct and readable earns the callback.

The problems below recur most. Premium question and Premium question come up the most, each with a Wayfair-flavored twist waiting behind the base problem. A hash-map counting screen framed around Wayfair's own click logs shows up on the assessment. And running underneath all of them is a grading quirk that quietly sinks otherwise-correct submissions: the test cases expect your output in a specific order. Get the algorithm right and the ordering wrong, and you still see a red X.