Hubspot coding interview
questions, leaked.
10 problems reported across recent Hubspot interviews. Top patterns: array, sorting, heap priority queue. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
HubSpot's coding interviews lean hard on arrays and sorting. Out of 10 reported problems, 6 are array-based and 5 involve sorting logic. You're looking at a mix of easy wins (Merge Sorted Array, Two Sum) and medium-hard problems that chain these patterns together (Merge Intervals, Meeting Rooms II, Top K Frequent Elements). The difficulty split is 3 easy, 5 medium, 2 hard. That's a ladder, not a cliff. The catch: medium problems here combine multiple topics (heaps, two pointers, greedy all in one problem). If you freeze mid-OA on a heap or two-pointer merge, StealthCoder runs invisibly and surfaces a working solution in seconds.
Top problems at Hubspot
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Merge Sorted Array | EASY | 100.0 | 53% | Array · Two Pointers · Sorting |
| 02 | Merge Two Sorted Lists | EASY | 92.9 | 67% | Linked List · Recursion |
| 03 | Two Sum | EASY | 87.1 | 56% | Array · Hash Table |
| 04 | Merge Intervals | MEDIUM | 87.1 | 49% | Array · Sorting |
| 05 | Maximum Number of Occurrences of a Substring | MEDIUM | 84.7 | 53% | Hash Table · String · Sliding Window |
| 06 | Find the Celebrity | MEDIUM | 75.1 | 48% | Two Pointers · Graph · Interactive |
| 07 | Meeting Rooms II | MEDIUM | 70.6 | 52% | Array · Two Pointers · Greedy |
| 08 | Top K Frequent Elements | MEDIUM | 56.5 | 65% | Array · Hash Table · Divide and Conquer |
| 09 | Merge k Sorted Lists | HARD | 56.5 | 57% | Linked List · Divide and Conquer · Heap (Priority Queue) |
| 10 | Find the K-Sum of an Array | HARD | 56.5 | 40% | Array · Sorting · Heap (Priority Queue) |
Frequencies derived from public community-tagged interview reports. Click a row to view on LeetCode.
You have a week, maybe less. You can't out-grind the list above. StealthCoder runs invisibly during the actual Hubspot OA. The proctor cannot see it. Screen share cannot detect it. Built by an Amazon engineer who realized the OA tests how well you memorized 200 problems, not how well you code.
Get StealthCoder- array6 · 60%
- sorting5 · 50%
- heap priority queue4 · 40%
- two pointers3 · 30%
- hash table3 · 30%
- linked list2 · 20%
- divide and conquer2 · 20%
- graph1 · 10%
- interactive1 · 10%
- string1 · 10%
Array manipulation dominates the interview. Every problem touches arrays; most also need sorting or a secondary pattern (hash tables, heaps, two pointers). Sorting appears in 5 problems and often decides whether your solution is clean or messy. Heaps and hash tables each show up in 4 problems, usually in the medium-hard range. Two pointers is the third pillar, handling both the easy baseline (Merge Sorted Array) and medium-level optimizations (Meeting Rooms II). Start by drilling Merge Sorted Array and Two Sum to build confidence. Then move to Merge Intervals and Meeting Rooms II, which feel harder but reuse the same merging and pointer logic you've already practiced. Top K Frequent Elements and Merge k Sorted Lists are the ceiling. If you hit a wall on heaps or multi-step divide-and-conquer during your live assessment, StealthCoder is your hedge.
Companies with similar patterns
If you prepped for Hubspot, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Hubspot.
Memorizing every problem above in a week is a fantasy. StealthCoder is the hedge: an AI overlay that's invisible during screen share. It reads the problem on screen and surfaces a working solution in under 2 seconds. Built by an Amazon engineer who realized the OA tests how well you memorized 200 problems, not how well you code. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Hubspot interview FAQ
What should I study first for HubSpot's coding interview?+
Arrays and sorting. 6 out of 10 problems are array-based, and 5 involve sorting. Start with Merge Sorted Array and Two Sum (both easy), then move to Merge Intervals and Meeting Rooms II. These build the foundation for the harder problems.
How much do I need to know about heaps for this interview?+
Heaps appear in 4 problems, mostly medium-hard (Meeting Rooms II, Top K Frequent Elements, Merge k Sorted Lists). You don't need expert-level heap theory, but you need to be comfortable with priority queues for ranking and merging tasks. It's a secondary pattern, not the main focus.
Is two pointers enough of a topic to drill separately?+
Yes. It shows up in 3 problems and appears in both easy and medium questions (Merge Sorted Array, Meeting Rooms II). Master the pattern of advancing pointers inward or in tandem to compare or merge data. It's simpler than heaps but no less critical.
What's the hardest problem I might face, and how should I prep for it?+
Merge k Sorted Lists or Find the K-Sum of an Array. Both combine divide-and-conquer with heaps or sorting. If you haven't seen the pattern, practice Merge Intervals and Top K Frequent Elements first. They teach the merging and selection logic you'll need.
Should I memorize solutions or understand patterns?+
Understand patterns. HubSpot's interview reuses merge, sort, and heap logic across multiple problems. If you understand why Merge Sorted Array works, you'll recognize the same idea in Merge Intervals and Meeting Rooms II. That's faster than rote memorization.