Valve coding interview
questions, leaked.
4 problems reported across recent Valve interviews. Top patterns: string, greedy, queue. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
Valve's interview process is tight. You're looking at four problems total, which means they're testing depth over breadth. Three of them are medium difficulty, and one is easy. String manipulation dominates the question pool, appearing in two problems, so you need to be sharp on parsing, greedy logic, and queue operations. The good news: there's no hard problems reported. The catch: medium-difficulty problems at Valve still require clean code and solid fundamentals. If you hit a wall during the live assessment, StealthCoder runs invisibly behind the screen, surfacing a working solution in seconds so you don't tank the round.
Top problems at Valve
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Dota2 Senate | MEDIUM | 100.0 | 49% | String · Greedy · Queue |
| 02 | String to Integer (atoi) | MEDIUM | 88.0 | 19% | String |
| 03 | Deep Merge of Two Objects | MEDIUM | 66.2 | 64% | |
| 04 | Design Parking System | EASY | 66.2 | 87% | Design · Simulation · Counting |
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 Valve 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 StealthCoderThe topic distribution tells you exactly where to focus. String problems appear twice, and both involve non-trivial logic: one pairs string manipulation with greedy and queue thinking (Dota2 Senate), the other is a classic parsing challenge (String to Integer). That's 50 percent of the interview right there. Design and simulation round out the picture with the parking system problem, a systems-design lightweight that tests your ability to model state cleanly. Greedy, queue, and counting each appear once. The difficulty skew (75 percent medium) means you can't just memorize solutions. You need to understand why the greedy choice works, how to leverage a queue for ordering, and how to count state transitions. Drill string problems first, then move to greedy queue combinations. When you sit down for the assessment, StealthCoder is your hedge if a string parsing edge case blindsides you.
Companies with similar patterns
If you prepped for Valve, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Valve.
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.
Valve interview FAQ
How many string problems should I expect at Valve?+
Two out of four reported problems focus on strings. That's half the interview. One is pure parsing (String to Integer), the other combines strings with greedy and queue logic (Dota2 Senate). Practice both patterns: straightforward manipulation and strings as state for algorithmic problems.
Is there a hard problem on Valve's interview?+
No hard problems have been reported in the dataset. The difficulty is split 25 percent easy, 75 percent medium. That doesn't mean the problems are trivial. The three medium problems require solid understanding of greedy logic, queue operations, and design principles, not just pattern matching.
What should I study first for a Valve interview?+
Start with string manipulation, since it appears in two problems. Then study greedy algorithms combined with queue operations, which shows up in Dota2 Senate. Finish with a quick systems-design pass using the parking system problem as your model. You're looking at one week, so prioritize string and greedy first.
Do I need to know design patterns for Valve?+
Yes, but not complex ones. The Design Parking System problem tests your ability to model state and count resources cleanly. It's a lightweight systems problem. You need to be comfortable with classes, state management, and simulation logic, not distributed systems.
What topics can I skip preparing for?+
Based on reported problems, dynamic programming, trees, graphs, and recursion don't appear in this dataset. You could skip them if you're timing-constrained, but don't ignore string, greedy, queue, and basic design fundamentals. Those are non-negotiable.