Gusto Coding Interview Questions
25 Gusto coding interview problems with full optimal solutions — 8 easy, 12 medium, 5 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an Gusto interviewer values, and a FAQ section.
Showing 9 problems of 25
- #1easyfrequently asked
1. Two Sum
Find the two indices whose values sum to a target. Gusto uses this as a warm-up to see if you think in hash maps before brute force — they care about naming, clean early returns, and whether you'd write a test for the no-solution case.
- #3mediumfrequently asked
3. Longest Substring Without Repeating Characters
Find the length of the longest substring with all unique characters. Gusto asks this as a sliding-window archetype — they want to see a clean window-shrink step that jumps the left pointer past the duplicate, not just nudges it one step.
- #15mediumfrequently asked
15. 3Sum
Find all unique triplets in the array that sum to zero. Gusto asks this to push beyond Two Sum — they want to see you sort first, lock one element, then use two pointers on the remainder while carefully skipping duplicates.
- #20easyfrequently asked
20. Valid Parentheses
Check whether a string of brackets is properly nested and closed. Gusto asks this to test stack intuition and clean code — they want to see a minimal bracket map and early exits, not a sprawling switch statement.
- #56mediumfrequently asked
56. Merge Intervals
Merge all overlapping intervals. Gusto's scheduling and payroll features make this a naturally grounded problem — think PTO blocks, pay-period windows, or benefits-eligibility ranges. They want clean comparator logic and a crisp overlap condition.
- #146mediumfrequently asked
146. LRU Cache
Design a cache that evicts the least-recently-used item when it's full. Gusto asks this because caching is real infrastructure in their payroll platform — they want to see the hash map + doubly-linked list composition and hear you explain why each data structure is needed before writing any code.
- #206easyfrequently asked
206. Reverse Linked List
Reverse a singly linked list in-place. Gusto uses this to test pointer manipulation fundamentals and to see whether candidates can articulate the three-variable dance (prev, curr, next) before touching the keyboard.
- #238mediumfrequently asked
238. Product of Array Except Self
Compute, for each index, the product of all other elements — without using division. Gusto asks this to test whether candidates see the prefix-suffix decomposition and can then optimise it to O(1) extra space by computing the suffix product on the fly.
- #322mediumfrequently asked
322. Coin Change
Find the minimum number of coins needed to make up an amount. Gusto's payroll and benefits domain makes this a grounded problem — think minimum transaction splits for expense reimbursement. They want bottom-up DP with a clear recurrence, not naive recursion.