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 13 problems of 25
- #1easyfoundational
1. Two Sum
Given an array of integers and a target, return indices of two numbers that add to the target.
- #2easyfoundational
2. Valid Parentheses
Determine if a string of brackets is properly opened and closed in the correct order.
- #3easyfoundational
3. Merge Two Sorted Lists
Merge two sorted linked lists into one sorted list by splicing nodes together.
- #4easyfoundational
4. Remove Duplicates from Sorted Array
Remove duplicates in-place from a sorted array and return the new length.
- #5easyfoundational
5. Remove Element
Remove all occurrences of a value in-place from an array and return the new length.
- #6easyfoundational
6. Search Insert Position
Return the index where a target should be inserted in a sorted array to keep it sorted.
- #7easyfoundational
7. Maximum Subarray
Find the contiguous subarray with the largest sum and return that sum.
- #8easyfoundational
8. Plus One
Increment an integer represented as a digit array by one and return the resulting digits.
- #9easyfoundational
9. Merge Sorted Array
Merge two sorted integer arrays in-place such that the result is also sorted.
- #10easyfoundational
10. Binary Tree Inorder Traversal
Return the inorder (left, root, right) traversal of a binary tree's node values.
- #11easyfoundational
11. Same Tree
Determine whether two binary trees are structurally identical with the same values.
- #15easyfoundational
15. Reverse Linked List
Reverse a singly linked list iteratively or recursively — a fundamental pointer-manipulation problem that Brex uses as a warm-up in onsite coding screens.
- #23easyfoundational
23. Contains Duplicate
Detect whether any value appears at least twice in an array — a hash set warm-up that Brex uses to establish baseline data structure fluency.