Karat coding interview
questions, leaked.
15 problems reported across recent Karat interviews. Top patterns: array, hash table, string. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
Karat runs a brutal screening interview. Fifteen problems reported, nine at medium difficulty. Array problems dominate the list (12 out of 15), but hash-table and string patterns show up constantly as secondary topics. You're facing a live coding session where the proctor watches every keystroke. Most candidates panic on the medium problems because they haven't drilled the exact patterns Karat loves. If you blank mid-assessment, StealthCoder runs invisibly on screen and surfaces a working solution in seconds, keeping you moving while the proctor sees nothing.
Top problems at Karat
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Text Justification | HARD | 100.0 | 48% | Array · String · Simulation |
| 02 | Check if Every Row and Column Contains All Numbers | EASY | 89.6 | 53% | Array · Hash Table · Matrix |
| 03 | Find Words That Can Be Formed by Characters | EASY | 88.5 | 71% | Array · Hash Table · String |
| 04 | Word Search | MEDIUM | 86.1 | 45% | Array · String · Backtracking |
| 05 | Alert Using Same Key-Card Three or More Times in a One Hour Period | MEDIUM | 80.2 | 46% | Array · Hash Table · String |
| 06 | Course Schedule | MEDIUM | 60.9 | 49% | Depth-First Search · Breadth-First Search · Graph |
| 07 | Ransom Note | EASY | 60.9 | 65% | Hash Table · String · Counting |
| 08 | Maximal Square | MEDIUM | 55.4 | 49% | Array · Dynamic Programming · Matrix |
| 09 | Number of Islands | MEDIUM | 55.4 | 62% | Array · Depth-First Search · Breadth-First Search |
| 10 | Valid Sudoku | MEDIUM | 55.4 | 62% | Array · Hash Table · Matrix |
| 11 | Subdomain Visit Count | MEDIUM | 47.6 | 77% | Array · Hash Table · String |
| 12 | Word Search II | HARD | 47.6 | 37% | Array · String · Backtracking |
| 13 | Course Schedule II | MEDIUM | 47.6 | 53% | Depth-First Search · Breadth-First Search · Graph |
| 14 | Jump Game | MEDIUM | 47.6 | 39% | Array · Dynamic Programming · Greedy |
| 15 | Two Sum | EASY | 47.6 | 56% | Array · Hash Table |
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 Karat OA. The proctor cannot see it. Screen share cannot detect it. Built by a senior engineer who knows the OA is theater. This is the script.
Get StealthCoder- array12 · 80%
- hash table7 · 47%
- string7 · 47%
- matrix6 · 40%
- depth first search4 · 27%
- counting3 · 20%
- breadth first search3 · 20%
- backtracking2 · 13%
- dynamic programming2 · 13%
- graph2 · 13%
Arrays aren't just about iteration here. Word Search, Maximal Square, Number of Islands, and Valid Sudoku all merge arrays with deeper patterns (backtracking, DP, graph traversal). Hash-table and string problems cluster around counting and lookup operations (Ransom Note, Two Sum, Subdomain Visit Count, Find Words That Can Be Formed by Characters). You need to recognize when a problem is really about "build a map to optimize queries" versus "iterate and check." Graph and topological-sort problems (Course Schedule, Course Schedule II) appear twice but aren't the majority. The two hard problems (Text Justification, Word Search II) test endurance and detail work under pressure. Drill arrays and hash-tables first, because they're your bread and butter. When you hit a medium graph or backtracking problem live and your mind goes blank, StealthCoder is your safety net, solving it while you stay composed.
Companies with similar patterns
If you prepped for Karat, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Karat.
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 a senior engineer who knows the OA is theater. This is the script. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Karat interview FAQ
How many array problems should I solve before my Karat interview?+
Array appears in 12 of 15 reported problems. Solve at least Word Search, Maximal Square, Number of Islands, and Valid Sudoku multiple times. These combine arrays with DFS, DP, and matrix logic. Two Sum and Check if Every Row and Column Contains All Numbers cover the hash-table variant. You're looking at 8-10 solid array drills minimum.
Do I need to study graph algorithms for Karat?+
Graph problems appear twice (Course Schedule, Course Schedule II). Both use topological sort and DFS/BFS. If you have time after nailing arrays and hash-tables, study topological sort. Otherwise, graph is lower frequency relative to array patterns. It's worth knowing, but not your first priority.
What's the difference between Karat's hard problems and the medium ones?+
Hard problems (Text Justification, Word Search II) require careful simulation and edge-case handling. Text Justification is string formatting logic. Word Search II uses backtracking plus trie optimization. Most medium problems test one clear pattern. Hard problems test pattern recognition plus implementation stamina. Expect complexity in execution, not just algorithm choice.
Should I focus on hash-table if I'm weak on arrays?+
No. Arrays appear in 80% of the problem set. Hash-tables show up in 7 of 15, often paired with arrays or strings. Arrays are your foundation. Master Two Sum and Check if Every Row and Column Contains All Numbers as your hash-table entry points, then graduate to Ransom Note and Subdomain Visit Count for string-counting combos.
How should I approach the backtracking and DFS problems?+
Word Search and Word Search II both use DFS/backtracking. Word Search is medium and a good drill; Word Search II is hard and requires trie knowledge. Number of Islands also uses DFS but on a grid. Practice DFS on grids first (Islands), then move to backtracking with character constraints (Word Search). Both patterns show up together in Karat assessments.