Deloitte coding interview
questions, leaked.
27 problems reported across recent Deloitte interviews. Top patterns: array, database, string. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
Deloitte's assessment pulls from 27 problems split almost evenly between easy and medium, with one curveball hard. Arrays dominate at 10 problems, but you're also seeing database queries, strings, and dynamic programming mixed in. The distribution is wide: you could hit Two Sum on one screen and Merge k Sorted Lists on the next. If you're testing soon, you can't memorize your way through this. StealthCoder is the safety net for whatever pattern you haven't drilled yet, working invisibly during the live assessment when your mind goes blank on that database join or two-pointer problem.
Top problems at Deloitte
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Change Null Values in a Table to the Previous Value | MEDIUM | 100.0 | 52% | Database |
| 02 | Two Sum | EASY | 97.3 | 56% | Array · Hash Table |
| 03 | Merge k Sorted Lists | HARD | 91.0 | 57% | Linked List · Divide and Conquer · Heap (Priority Queue) |
| 04 | Valid Parentheses | EASY | 82.5 | 42% | String · Stack |
| 05 | Container With Most Water | MEDIUM | 76.9 | 58% | Array · Two Pointers · Greedy |
| 06 | Second Highest Salary | MEDIUM | 76.9 | 44% | Database |
| 07 | Longest Palindromic Substring | MEDIUM | 76.9 | 36% | Two Pointers · String · Dynamic Programming |
| 08 | Palindrome Number | EASY | 76.9 | 59% | Math |
| 09 | Rising Temperature | EASY | 69.7 | 50% | Database |
| 10 | Reverse Integer | MEDIUM | 69.7 | 30% | Math |
| 11 | Climbing Stairs | EASY | 69.7 | 54% | Math · Dynamic Programming · Memoization |
| 12 | Managers with at Least 5 Direct Reports | MEDIUM | 69.7 | 49% | Database |
| 13 | Merge Intervals | MEDIUM | 59.5 | 49% | Array · Sorting |
| 14 | Minimum Time to Repair Cars | MEDIUM | 59.5 | 60% | Array · Binary Search |
| 15 | Pascal's Triangle | EASY | 59.5 | 77% | Array · Dynamic Programming |
| 16 | Majority Element | EASY | 59.5 | 66% | Array · Hash Table · Divide and Conquer |
| 17 | Best Time to Buy and Sell Stock | EASY | 59.5 | 55% | Array · Dynamic Programming |
| 18 | Find Customer Referee | EASY | 59.5 | 72% | Database |
| 19 | Article Views I | EASY | 59.5 | 77% | Database |
| 20 | Longest Common Prefix | EASY | 59.5 | 45% | String · Trie |
| 21 | Reverse Words in a String | MEDIUM | 59.5 | 52% | Two Pointers · String |
| 22 | Max Consecutive Ones | EASY | 59.5 | 62% | Array |
| 23 | Kth Largest Element in an Array | MEDIUM | 59.5 | 68% | Array · Divide and Conquer · Sorting |
| 24 | Coin Change | MEDIUM | 59.5 | 46% | Array · Dynamic Programming · Breadth-First Search |
| 25 | Edit Distance | MEDIUM | 59.5 | 59% | String · Dynamic Programming |
| 26 | Reverse Linked List | EASY | 59.5 | 79% | Linked List · Recursion |
| 27 | Longest Substring Without Repeating Characters | MEDIUM | 59.5 | 37% | Hash Table · String · Sliding Window |
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 Deloitte OA. The proctor cannot see it. Screen share cannot detect it. Made by an Amazon engineer who watched the leaked-problem repo become an industry secret. He decided you should have it too.
Get StealthCoder- array10 · 37%
- database6 · 22%
- string6 · 22%
- dynamic programming6 · 22%
- two pointers3 · 11%
- sorting3 · 11%
- divide and conquer3 · 11%
- hash table3 · 11%
- math3 · 11%
- linked list2 · 7%
The heavy array focus (10 problems) means your foundation has to be solid on indexing, sliding windows, and prefix logic. But don't sleep on database: 6 problems means you're probably hitting at least one SQL query for salary rankings or temperature comparisons. Strings and dynamic programming are both at 6, and they often overlap (Longest Palindromic Substring). The medium tier is where most of the weight is, so you're not drowning in easy wins. Two-pointers, sorting, and divide-and-conquer are lower frequency, which is good: you can triage harder patterns first. If you blank on a two-pointer optimization mid-assessment, StealthCoder surfaces the approach in seconds without the proctor catching it.
Companies with similar patterns
If you prepped for Deloitte, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Deloitte.
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 an Amazon engineer who watched the leaked-problem repo become an industry secret. He decided you should have it too. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Deloitte interview FAQ
Should I study database before arrays for Deloitte?+
No. Arrays appear in 10 of 27 problems. Start there: Two Sum, Merge Intervals, Container With Most Water. Once arrays are solid, tackle the 6 database problems. Database is required but lower volume than array patterns.
Is dynamic programming required for this assessment?+
Yes. DP appears in 6 problems and overlaps with strings (Longest Palindromic Substring) and arrays (Pascal's Triangle, Climbing Stairs). It's not optional. Spend time on memoization and bottom-up approaches.
How many easy problems should I solve before attempting medium?+
There are 13 easy problems in the dataset. Solve all of them first. They cover array, string, math, and database basics. They're not filler; they're foundation. The 13 medium problems will feel much faster once you've locked in the easy patterns.
What's the hardest problem I might see, and is it worth drilling?+
Merge k Sorted Lists. It's the single hard problem reported. It hits linked lists, divide-and-conquer, and heaps. Drill it if you have time, but prioritize nailing the 13 medium problems first. One hard problem is usually a tiebreaker.
Do I need to be strong in all topics or can I skip some?+
You can't skip arrays, strings, or database. Those are 22 of 27. Two-pointers, sorting, and greedy are lower frequency and can be secondary. Focus first on array patterns and database queries, then round out with string and DP.