Blizzard coding interview
questions, leaked.
2 problems reported across recent Blizzard interviews. Top patterns: dynamic programming, string, stack. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
Blizzard's coding assessments are lean but deceptive. With only two reported problems across their OA, you're looking at depth over volume. One medium problem sits right at the boundary of what candidates typically blank on under time pressure. The other is an easy warm-up that sets a false sense of security. Both problems hinge on dynamic programming, so this isn't a broad survey of patterns. You'll need to think fast and execute cleanly. If you hit a wall on the live assessment, StealthCoder runs invisibly during screen share and surfaces a working solution in seconds, giving you the safety net to move forward without panic.
Top problems at Blizzard
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Valid Parenthesis String | MEDIUM | 100.0 | 39% | String · Dynamic Programming · Stack |
| 02 | Best Time to Buy and Sell Stock | EASY | 100.0 | 55% | Array · 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 Blizzard 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- dynamic programming2 · 100%
- string1 · 50%
- stack1 · 50%
- greedy1 · 50%
- array1 · 50%
Dynamic programming dominates the data, appearing in both problems. That's your primary drill target. The medium problem, Valid Parenthesis String, combines string manipulation with greedy and stack thinking on top of DP logic. That's the one that catches people mid-assessment. The easy problem, Best Time to Buy and Sell Stock, is a confidence builder but don't treat it as trivial under time pressure. What you're seeing here is a signal: Blizzard cares about your ability to model state and optimize, not just brute-force solutions. Array and greedy logic appear once each but should be warm-ups. Since the problem set is this small, expect your interviewer to dig deeper into your thought process on the DP solutions. StealthCoder is the hedge if you can't immediately recall the state transition or recurrence relation during the live OA.
Companies with similar patterns
If you prepped for Blizzard, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Blizzard.
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.
Blizzard interview FAQ
Should I focus only on dynamic programming for Blizzard?+
Yes, prioritize it heavily. Both reported problems use DP as a core component. Spend 70% of your drill time on DP patterns, state definition, and recurrence relations. The other topics (string, stack, greedy, array) appear less frequently, so treat them as supporting skills once you're solid on DP.
Is the easy problem enough to warm up with?+
It's a start, but don't skip it. Best Time to Buy and Sell Stock is straightforward under calm conditions, but nerves during a live OA can tank simple problems. Solve it a few times to build muscle memory. Then move straight to the medium problem.
What should I study first for Blizzard?+
Start with the medium problem, Valid Parenthesis String. It's the hardest thing they'll ask and combines multiple patterns. Once you can solve it cleanly with DP, the easy problem becomes a formality. This inverts the normal advice, but Blizzard's small problem set means you can't afford to leave the medium unsolved.
How much time should I spend on stack and greedy?+
They appear in context of the medium problem, so learn them as support skills, not standalone. Valid Parenthesis String forces you to think about when to use greedy vs. when to fall back to DP. Understanding that interplay is more valuable than drilling greedy algorithms in isolation.
Will two problems be enough to prepare?+
Not entirely. Two problems give you a direction but not a full practice set. After you solve the reported problems, drill similar DP patterns and string problems on your own. The reported problems are a signal of Blizzard's taste, not a complete picture of difficulty variance.