Coinbase - Software Engineer (Frontend) - CodeSignal OA

Description:

Level: IC4

Education: Master’s

Years of Experience (YOE): 6

Questions Asked:

Nested Iterator Problem:

Implement a class that flattens a nested list of integers (e.g. [1, [2, [3, 4]], 5]) into a flat iterator with two methods: hasNext() and next().

Additional Notes:

The focus was on clean code, class design, and recursion. The interviewer asked follow-up questions on how the solution could be extended to handle different data types or implement lazy evaluation.