FactSet coding interview
questions, leaked.
5 problems reported across recent FactSet interviews. Top patterns: string, stack, greedy. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
FactSet's assessment leans heavily on string manipulation and stack patterns. You're looking at five problems across one easy and four mediums, with string, stack, and greedy dominating the distribution. That's not a broad survey of algorithms. It's a focused test on one specific skill: building solutions that track state efficiently and backtrack when needed. If you've drilled monotonic stacks and greedy string problems, you'll recognize the shape immediately. If not, you're walking in cold. StealthCoder runs invisibly during the live assessment and surfaces working solutions in seconds if you hit a wall on a pattern you haven't seen.
Top problems at FactSet
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Remove All Adjacent Duplicates in String II | MEDIUM | 100.0 | 60% | String · Stack |
| 02 | Remove Duplicate Letters | MEDIUM | 100.0 | 51% | String · Stack · Greedy |
| 03 | Smallest Subsequence of Distinct Characters | MEDIUM | 100.0 | 62% | String · Stack · Greedy |
| 04 | Happy Number | EASY | 63.3 | 58% | Hash Table · Math · Two Pointers |
| 05 | Increasing Triplet Subsequence | MEDIUM | 63.3 | 39% | Array · Greedy |
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 FactSet OA. The proctor cannot see it. Screen share cannot detect it. Made by a working Amazon engineer who got tired of watching qualified friends bomb OAs they'd solve cold in an IDE.
Get StealthCoder- string3 · 60%
- stack3 · 60%
- greedy3 · 60%
- monotonic stack2 · 40%
- hash table1 · 20%
- math1 · 20%
- two pointers1 · 20%
- array1 · 20%
Three of the five problems blend string manipulation with stack logic, often adding a greedy constraint on top. Remove All Adjacent Duplicates in String II, Remove Duplicate Letters, and Smallest Subsequence of Distinct Characters are variations on the same core idea: maintain a stack, conditionally pop elements, process strings left to right. The easy problem, Happy Number, is a curveball that tests cycle detection via hash table instead. Increasing Triplet Subsequence breaks the stack pattern and hits greedy plus array reasoning. Study the three string-stack problems first because they're the spine of the test. Monotonic stack is the architecture you'll use twice, and greedy is the decision logic you'll apply repeatedly. By the time you hit the assessment, these patterns should feel automatic. StealthCoder is your hedge if the problem statement throws a twist you didn't anticipate during prep.
Companies with similar patterns
If you prepped for FactSet, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass FactSet.
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 Amazon engineer who got tired of watching qualified friends bomb OAs they'd solve cold in an IDE. Works on HackerRank, CodeSignal, CoderPad, and Karat.
FactSet interview FAQ
How many string-stack problems should I solve before the FactSet assessment?+
At least three complete walkthroughs. Remove All Adjacent Duplicates, Remove Duplicate Letters, and Smallest Subsequence hit the core pattern. FactSet's distribution shows string and stack appear in three problems each, so drilling these three covers roughly 60 percent of the assessment. The monotonic-stack topic appears twice, and both times it's layered on top of string logic.
Is Happy Number worth drilling, or should I focus on stacks?+
It's one of five problems, so don't skip it. Happy Number tests a different skill: cycle detection and hash table logic. It's also marked EASY, so it's a confidence builder. Spend 20 minutes on it after nailing the stack problems. The assessment has 80 percent medium difficulty, so stacks are your priority, but this one can be a quick point.
What's the best order to study these topics before the test?+
Start with string basics and stack mechanics (push, pop, peek). Then combine them: practice building a stack while iterating a string. Add greedy logic next, because Remove Duplicate Letters and Smallest Subsequence require you to decide whether to pop an element based on future characters. Finish with monotonic-stack theory. Two pointers and hash table are secondary.
Do I need to study greedy algorithms separately, or is it covered in the stack problems?+
The stack problems teach greedy indirectly. Remove Duplicate Letters and Smallest Subsequence both use greedy decisions inside a stack loop. You'll learn it faster by solving those two problems than by studying greedy as an abstract topic first. But understand the greedy principle: make the locally optimal choice (e.g., pop a larger character if a smaller one is coming) to build the globally optimal result.
Is one week enough to prepare for FactSet's assessment?+
Yes, because the problem set is narrow. Five total problems, three of which follow the same pattern. You can solve each of the three string-stack problems in 30-45 minutes, understand the pattern in another 90 minutes, and drill variations in two days. Spend the rest of the week on Happy Number and Increasing Triplet Subsequence. By day five you should be able to recognize the pattern and outline a solution in under a minute.