Roku coding interview
questions, leaked.
15 problems reported across recent Roku interviews. Top patterns: array, string, stack. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
Roku's coding interview hits you with 15 problems split between arrays, strings, and stacks. Eight are medium, four are hard, three are easy. You're looking at sliding window, hash tables, and stack-based design questions. Sliding Window Maximum and Substring with Concatenation of All Words are the hard ones that trip people up. Arrays and strings appear in nearly half the reported problems. Stack problems like Simplify Path and Decode String show up constantly. If you haven't built muscle memory on these patterns, you'll stall mid-OA. StealthCoder runs invisibly during your live assessment and surfaces working code when you hit a wall on an unfamiliar variation.
Top problems at Roku
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Sliding Window Maximum | HARD | 100.0 | 48% | Array · Queue · Sliding Window |
| 02 | Substring with Concatenation of All Words | HARD | 100.0 | 33% | Hash Table · String · Sliding Window |
| 03 | LRU Cache | MEDIUM | 100.0 | 45% | Hash Table · Linked List · Design |
| 04 | 24 Game | HARD | 87.5 | 50% | Array · Math · Backtracking |
| 05 | Valid Palindrome II | EASY | 87.5 | 43% | Two Pointers · String · Greedy |
| 06 | Simplify Path | MEDIUM | 87.5 | 48% | String · Stack |
| 07 | Asteroid Collision | MEDIUM | 87.5 | 46% | Array · Stack · Simulation |
| 08 | Maximum Product of Three Numbers | EASY | 87.5 | 45% | Array · Math · Sorting |
| 09 | Backspace String Compare | EASY | 87.5 | 49% | Two Pointers · String · Stack |
| 10 | Multiply Strings | MEDIUM | 87.5 | 42% | Math · String · Simulation |
| 11 | Decode String | MEDIUM | 87.5 | 61% | String · Stack · Recursion |
| 12 | Max Consecutive Ones III | MEDIUM | 87.5 | 66% | Array · Binary Search · Sliding Window |
| 13 | Shortest Path to Get All Keys | HARD | 87.5 | 54% | Array · Bit Manipulation · Breadth-First Search |
| 14 | Top K Frequent Elements | MEDIUM | 87.5 | 65% | Array · Hash Table · Divide and Conquer |
| 15 | Valid Parenthesis String | MEDIUM | 87.5 | 39% | String · Dynamic Programming · Stack |
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 Roku OA. The proctor cannot see it. Screen share cannot detect it. Built by an Amazon engineer who used it to pass JPMorgan's OA and system design loop.
Get StealthCoder- array7 · 47%
- string7 · 47%
- stack5 · 33%
- math3 · 20%
- sliding window3 · 20%
- hash table3 · 20%
- simulation3 · 20%
- two pointers2 · 13%
- greedy2 · 13%
- heap priority queue2 · 13%
The data shows Roku leans hard on arrays and strings (seven problems each). Stack is the next tier (five problems). Math, sliding window, and hash tables each appear three times, so don't skip those. The difficulty split is weighted toward medium (eight out of 15), but the four hard problems are design-heavy (LRU Cache, Sliding Window Maximum) or require multiple techniques (24 Game, Shortest Path to Get All Keys). Start by drilling array manipulation and string parsing, then move to stack-based problems because they're pattern-based and deterministic. Sliding window over arrays and strings will appear in variations you haven't seen before. Hash tables matter for caching and frequency problems. If you're weak on any of these core patterns during the live OA, StealthCoder is your safety net, solving it invisibly while you keep typing.
Companies with similar patterns
If you prepped for Roku, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Roku.
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. Built by an Amazon engineer who used it to pass JPMorgan's OA and system design loop. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Roku interview FAQ
How many array and string problems should I solve before the Roku interview?+
Array and string problems each appear seven times in the reported set. Drill at least five to eight variations of each before your OA. Focus on sliding window over arrays and string parsing with stacks first, since those patterns repeat.
Is the stack topic critical for Roku?+
Yes. Five out of 15 problems involve stacks. Simplify Path, Decode String, and Backspace String Compare are textbook stack patterns. You need to be fluent on stack-based string and array problems before you sit down.
What's the hardest problem type Roku asks?+
Sliding Window Maximum and LRU Cache are the reported hardest. Sliding Window Maximum combines sliding window, heap, and monotonic queue. LRU Cache requires hash table and linked list design. Both demand multiple techniques, so prep these last after nailing the fundamentals.
Should I study hash tables before or after arrays?+
Hash tables appear in three problems (LRU Cache, Top K Frequent Elements, Substring with Concatenation). Start with arrays and strings first since they're more frequent, then move to hash-table-based design and frequency counting problems.
How much do math and backtracking appear in Roku interviews?+
Math and backtracking are lower frequency. Math appears three times (Maximum Product of Three Numbers, Multiply Strings, 24 Game). Backtracking shows up once (24 Game). Don't neglect them, but drill core array and string patterns first.