Stripe·Software Engineer·Technical Phone Screen
- Implement a function that performs an inner join on two CSV-like datasets keyed by a given field name. Rows should only appear in the output if the key exists in both datasets, the output row should merge the two matching rows without duplicating the key column, and the ordering from the first dataset should be preserved. The function also accepts a flag to control behavior on unmatched rows.
“Spent the first few minutes just talking through what an inner join actually means in this context before touching any code, which I think helped.”