Brex Coding Interview Questions
25 Brex coding interview problems with full optimal solutions — 13 easy, 9 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 Brex interviewer values, and a FAQ section.
Showing 9 problems of 25
- #12mediumfoundational
12. Maximum Product Subarray
Find the contiguous subarray with the largest product — tests dynamic programming with sign-flip tracking, relevant to multi-currency gain/loss computations at Brex.
- #13mediumfoundational
13. Find Minimum in Rotated Sorted Array
Locate the minimum element in a rotated sorted array in O(log n) — tests binary search intuition commonly seen in Brex's infrastructure and data pipeline rounds.
- #14mediumfoundational
14. Number of Islands
Count connected land regions in a 2D grid using BFS or DFS — a graph traversal staple that Brex uses to assess structured problem decomposition skills.
- #16mediumfoundational
16. Course Schedule
Detect a cycle in a directed graph of course prerequisites — directly mirrors approval-chain and spend-policy dependency validation at Brex.
- #17mediumfoundational
17. Implement Trie (Prefix Tree)
Build a prefix tree supporting insert, search, and startsWith — tests data structure design skills relevant to Brex's merchant category autocomplete and rules-engine keyword matching.
- #18mediumfoundational
18. Coin Change
Find the fewest coins to make a target amount — a classic unbounded knapsack DP that Brex maps to spend-limit decomposition and multi-currency rounding problems.
- #19mediumfoundational
19. Longest Increasing Subsequence
Find the length of the longest strictly increasing subsequence — a DP / patience-sort problem that Brex interviewers use to test algorithmic depth and optimization awareness.
- #21mediumfoundational
21. Word Break
Determine whether a string can be segmented into dictionary words — a DP string problem Brex applies to category-keyword parsing in its rules engine.
- #24mediumfoundational
24. Product of Array Except Self
Return an output array where each element is the product of all other elements — a prefix/suffix product trick Brex tests in financial aggregation and ledger balance contexts.