Commvault coding interview
questions, leaked.
11 problems reported across recent Commvault interviews. Top patterns: dynamic programming, array, string. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
Commvault pulls from a tight list of 11 problems, and 9 of them are medium difficulty. You're not walking into a gauntlet of easy warm-ups. The topics cluster hard around dynamic programming and arrays, with string and binary search as secondary heavy hitters. If you blank on how to code a DP recurrence or trace through a two-pointer array manipulation mid-assessment, StealthCoder runs invisibly during screen share and surfaces a working solution in seconds. That safety net matters when the proctor can't see your screen.
Top problems at Commvault
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Count Vowel Substrings of a String | EASY | 100.0 | 71% | Hash Table · String |
| 02 | Decode Ways | MEDIUM | 92.9 | 37% | String · Dynamic Programming |
| 03 | Reach a Number | MEDIUM | 92.9 | 44% | Math · Binary Search |
| 04 | Longest Increasing Subsequence | MEDIUM | 86.5 | 58% | Array · Binary Search · Dynamic Programming |
| 05 | Number of Longest Increasing Subsequence | MEDIUM | 82.5 | 50% | Array · Dynamic Programming · Binary Indexed Tree |
| 06 | Reverse Nodes in k-Group | HARD | 77.6 | 63% | Linked List · Recursion |
| 07 | Count Unreachable Pairs of Nodes in an Undirected Graph | MEDIUM | 77.6 | 49% | Depth-First Search · Breadth-First Search · Union Find |
| 08 | Rotating the Box | MEDIUM | 62.2 | 79% | Array · Two Pointers · Matrix |
| 09 | Longest Palindromic Substring | MEDIUM | 62.2 | 36% | Two Pointers · String · Dynamic Programming |
| 10 | Find Peak Element | MEDIUM | 62.2 | 47% | Array · Binary Search |
| 11 | Add Two Numbers | MEDIUM | 62.2 | 46% | Linked List · Math · Recursion |
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 Commvault OA. The proctor cannot see it. Screen share cannot detect it. Made by a working FAANG engineer who treats the OA the way companies treat hiring: as a game with rules you should know.
Get StealthCoder- dynamic programming4 · 36%
- array4 · 36%
- string3 · 27%
- binary search3 · 27%
- math2 · 18%
- linked list2 · 18%
- recursion2 · 18%
- two pointers2 · 18%
- binary indexed tree1 · 9%
- segment tree1 · 9%
Dynamic programming and arrays dominate the signal here, appearing in 4 problems each. String problems (3 total) lean DP-heavy: Decode Ways and Longest Palindromic Substring both require you to think in states and build bottom-up. Binary search (3 problems) pairs with DP on Longest Increasing Subsequence, and shows up standalone in Find Peak Element and Reach a Number. Linked-list problems hit harder (Reverse Nodes in k-Group is the hard outlier, Recursion required). The one easy problem, Count Vowel Substrings, is a hash-table warm-up you should breeze through. Your drill order: nail DP array patterns first, then string DP overlays, then binary search logic. If you haven't internalized LIS or two-pointer reversals by interview day, StealthCoder is your hedge for whatever didn't stick.
Companies with similar patterns
If you prepped for Commvault, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Commvault.
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. Made by a working FAANG engineer who treats the OA the way companies treat hiring: as a game with rules you should know. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Commvault interview FAQ
How many dynamic programming problems should I solve before a Commvault OA?+
At least 4 to 5 solid ones. They own 36% of the reported list, and they pair DP with arrays and strings. Decode Ways, Longest Increasing Subsequence, and Longest Palindromic Substring are non-negotiable. If DP isn't automatic, you'll lose time mid-interview.
Is binary search really necessary for Commvault?+
Yes. Three problems involve it, and it pairs with DP and arrays. Longest Increasing Subsequence often expects O(n log n) binary-search optimization, not just O(n2) DP. Study the pattern on Find Peak Element too. It's a core signal.
What about linked lists and recursion?+
Two linked-list problems appear, including Reverse Nodes in k-Group, which is hard and recursive. If you've never done k-group reversal, drill it separately. The recursion topic shows up 2 times total, so it's not dominant, but linked-list recursion is a precision skill.
Should I focus on the one easy problem first?+
No. Count Vowel Substrings is a hash-table gimme and should take you 5 minutes cold. Use your prep time on the 9 medium problems, especially DP and array patterns. The easy one is confidence, not education.
What if I get stuck on a DP or array problem during the live OA?+
StealthCoder solves it invisibly in real time during screen share. You get a working code outline in seconds, no proctor visibility. It's the insurance policy for patterns you didn't have time to drill or edge cases you missed.