ThoughtWorks coding interview
questions, leaked.
8 problems reported across recent ThoughtWorks interviews. Top patterns: string, dynamic programming, array. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
ThoughtWorks pulls from a tight, hard set of 8 problems, and they're not messing around. You're facing three hard problems that chain string manipulation, dynamic programming, and bit-level thinking. Three easy ones will look like a relief until you realize they're speed traps. The middle tier is sparse but punishing. If you blank on a bitmask or rolling-hash problem mid-assessment, StealthCoder runs invisibly and surfaces a working solution in seconds so you don't crater. Prep the string and DP overlap first. That's where ThoughtWorks' teeth are.
Top problems at ThoughtWorks
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Maximize the Number of Partitions After Operations | HARD | 100.0 | 27% | String · Dynamic Programming · Bit Manipulation |
| 02 | Maximum GCD-Sum of a Subarray | HARD | 100.0 | 36% | Array · Math · Binary Search |
| 03 | Number of Subarrays That Match a Pattern II | HARD | 100.0 | 32% | Array · Rolling Hash · String Matching |
| 04 | Number of Bit Changes to Make Two Integers Equal | EASY | 100.0 | 63% | Bit Manipulation |
| 05 | Best Time to Buy and Sell Stock | EASY | 73.0 | 55% | Array · Dynamic Programming |
| 06 | Longest Substring Without Repeating Characters | MEDIUM | 63.9 | 37% | Hash Table · String · Sliding Window |
| 07 | Valid Parentheses | EASY | 63.9 | 42% | String · Stack |
| 08 | Longest Palindromic Substring | MEDIUM | 63.9 | 36% | Two Pointers · String · Dynamic Programming |
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 ThoughtWorks OA. The proctor cannot see it. Screen share cannot detect it. Made for the engineer who has done the work but might still blank with a webcam pointed at him.
Get StealthCoder- string4 · 50%
- dynamic programming3 · 38%
- array3 · 38%
- bit manipulation2 · 25%
- bitmask1 · 13%
- math1 · 13%
- binary search1 · 13%
- number theory1 · 13%
- rolling hash1 · 13%
- string matching1 · 13%
String problems dominate the list at four appearances, and they're not basic validation. You'll see patterns that demand dynamic programming (substrings, partitions) plus hash-table speed. Dynamic programming and array topics tie at three each, but the hard problems use them in nasty combinations. Bit manipulation shows up twice and clusters in the hardest tier, so if bitwise operations aren't muscle memory, drill them now. The spread tells you ThoughtWorks values algorithmic depth over breadth. Focus on Longest Palindromic Substring and Longest Substring Without Repeating Characters first because those patterns appear embedded in the hard set. Math and number-theory problems are lower frequency but land in the hard tier, so expect them to be scorers. If you hit the live assessment unprepared on any hard problem, StealthCoder is your hedge.
Companies with similar patterns
If you prepped for ThoughtWorks, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass ThoughtWorks.
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 for the engineer who has done the work but might still blank with a webcam pointed at him. Works on HackerRank, CodeSignal, CoderPad, and Karat.
ThoughtWorks interview FAQ
Should I spend more time on bit manipulation or dynamic programming for ThoughtWorks?+
DP is heavier at three problems and threads through the hard set. Bit manipulation appears twice and only in the hardest tier. Start with DP, master string and array overlap, then circle back to bitmask and bit-flipping logic. They're both required for the hard problems, but DP unlocks more of the assessment.
What's the safest pattern to drill first for a ThoughtWorks assessment?+
Longest Palindromic Substring and Longest Substring Without Repeating Characters. Both sit at medium difficulty and teach the two-pointer and hash-table sliding-window tactics that ThoughtWorks reuses in harder variants. These are the foundation patterns here.
How many easy problems should I expect to solve cleanly?+
Three easy problems in the set, but two of them (Best Time to Buy and Sell Stock, Valid Parentheses) are speed checks, not freebies. Get those right fast. Number of Bit Changes is the actual breather, but it's testing bit manipulation, which also appears in the hard tier.
Is it worth learning rolling hash for ThoughtWorks?+
Yes. Rolling hash appears in one of the three hard problems (Number of Subarrays That Match a Pattern II) alongside string matching and hash functions. It's a lower-frequency topic overall, but it's glued to a hard problem you can't skip. One night of focused study pays off.
What topics can I safely skip or deprioritize?+
Math and number-theory appear once each in the hard tier, so you can't fully skip them, but they're not repeated. Stack shows up once in Valid Parentheses. Skip nothing, but if you're down to 48 hours, polish string and DP overlap before touching isolated topics.