Box coding interview
questions, leaked.
6 problems reported across recent Box interviews. Top patterns: hash table, string, heap priority queue. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
Box pulls from a tight rotation of six problems, and you'll see hash-tables, strings, and heaps dominate the assessment. Two are easy, three medium, one hard. That distribution sounds friendly until you realize the medium problems are dense: Top K Frequent Words alone touches array, hash-table, string, trie, sorting, heap, and bucket-sort. You're expected to know these patterns cold. If you blank on a heap implementation or the BFS twist in Word Ladder mid-assessment, StealthCoder runs invisibly and surfaces a working solution in seconds, so you don't crater.
Top problems at Box
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Number of 1 Bits | EASY | 100.0 | 75% | Divide and Conquer · Bit Manipulation |
| 02 | Top K Frequent Words | MEDIUM | 92.6 | 59% | Array · Hash Table · String |
| 03 | Word Ladder | HARD | 77.0 | 43% | Hash Table · String · Breadth-First Search |
| 04 | Kth Largest Element in a Stream | EASY | 66.8 | 60% | Tree · Design · Binary Search Tree |
| 05 | Event Emitter | MEDIUM | 58.8 | 74% | |
| 06 | Redundant Connection | MEDIUM | 58.8 | 66% | Depth-First Search · Breadth-First Search · Union Find |
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 Box OA. The proctor cannot see it. Screen share cannot detect it. Built by an Amazon engineer who realized the OA tests how well you memorized 200 problems, not how well you code.
Get StealthCoder- hash table2 · 33%
- string2 · 33%
- heap priority queue2 · 33%
- breadth first search2 · 33%
- divide and conquer1 · 17%
- bit manipulation1 · 17%
- array1 · 17%
- trie1 · 17%
- sorting1 · 17%
- bucket sort1 · 17%
The dataset is small but pattern-heavy. Hash-table, string, heap-priority-queue, and breadth-first-search each appear twice, which means Box values fluency in hash operations, string manipulation, and graph traversal. Start with hash-tables and strings since they're foundational and feed into the harder problems like Top K Frequent Words and Word Ladder. The single hard problem (Word Ladder) requires BFS plus hash-table setup, so practicing that combo first pays dividends. Bit-manipulation and divide-and-conquer show up once each, so they're lower priority unless you're aiming for confidence across the board. If you hit a knowledge gap in the live OA, StealthCoder is your safety net for the patterns you didn't have time to drill.
Companies with similar patterns
If you prepped for Box, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Box.
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 realized the OA tests how well you memorized 200 problems, not how well you code. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Box interview FAQ
How many hash-table problems should I solve before a Box assessment?+
Hash-table appears in 2 out of 6 reported problems. Solve at least 8 to 12 classic hash problems (two-sum, group anagrams, valid anagram). Box's problems blend hash-tables with other structures, so practice cross-topic patterns like hash plus heap (Top K Frequent Words) and hash plus BFS (Word Ladder).
Is practicing bit-manipulation necessary for Box?+
Bit-manipulation appears once (Number of 1 Bits), which is a quick-win easy problem. Spend one to two hours on bit basics (bitwise operators, counting set bits) but don't go deep. Prioritize hash-tables, strings, and heaps first, which have higher coverage.
What should I drill first for Box?+
Start with hash-tables and strings together, since both appear twice and feed into harder problems. Then move to heap-priority-queue and breadth-first-search. These four topics cover the majority of the reported assessment. Top K Frequent Words is the densest problem, so use it as your anchor drill.
Should I study union-find for Box?+
Union-find appears in one reported problem (Redundant Connection). If you know union-find basics, use it. If not, learn DFS or BFS solutions for graph cycle detection instead. Both solve the problem. Union-find is a nice-to-have, not essential.
How much time should I spend on sorting and bucket-sort?+
Sorting and bucket-sort each appear once, and both are embedded in Top K Frequent Words. Understand heap-based sorting and bucket-sort for Top K, but don't study them in isolation. Two to three hours of focused Top K practice covers both.