Monzo Coding Interview Questions
25 Monzo coding interview problems with full optimal solutions — 14 easy, 8 medium, 3 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an Monzo interviewer values, and a FAQ section.
Showing 8 problems of 25
- #15mediumfoundational
15. Longest Substring Without Repeating Characters
Find the longest run of unique characters in a merchant descriptor used for automatic categorization.
- #16mediumfoundational
16. Group Anagrams
Group merchant descriptor variants that share the same letters so they map to one category.
- #17mediumfoundational
17. LRU Cache
Design a fixed-capacity cache for hot account-balance lookups that evicts the least recently used entry.
- #18mediumfoundational
18. Coin Change
Find the fewest coin denominations needed to fund a savings-goal top-up of exactly amount pence.
- #19mediumfoundational
19. Product of Array Except Self
For each transaction, compute the product of all other transaction multipliers in O(n) without division.
- #20mediumfoundational
20. Kth Largest Element in an Array
Return the kth largest transaction amount in a stream from the customer's spending feed.
- #21mediumfoundational
21. Number of Islands
Count clusters of related accounts in a grid of customer/merchant connections.
- #22mediumfoundational
22. Top K Frequent Elements
Return the k merchant categories that appear most often in a customer's spending feed.