Anduril coding interview
questions, leaked.
32 problems reported across recent Anduril interviews. Top patterns: array, depth first search, breadth first search. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
Anduril's assessment hits you with 32 problems across medium and hard difficulty, and array manipulation dominates the list. You're looking at roughly 72% medium-difficulty problems, which means the bar isn't theoretical, it's pattern recognition under time pressure. Graph traversal (DFS/BFS) shows up constantly, and you'll need to recognize when to use union-find versus tree-based solutions. If you blank on a connected-components problem mid-assessment, StealthCoder runs invisibly and surfaces a working solution in seconds. The real edge isn't drilling every variant. It's knowing which patterns to recognize first and having a safety net when one doesn't stick.
Top problems at Anduril
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Number of Islands | MEDIUM | 100.0 | 62% | Array · Depth-First Search · Breadth-First Search |
| 02 | Maximum Number of Visible Points | HARD | 92.9 | 38% | Array · Math · Geometry |
| 03 | Video Stitching | MEDIUM | 92.9 | 52% | Array · Dynamic Programming · Greedy |
| 04 | Group Anagrams | MEDIUM | 88.3 | 71% | Array · Hash Table · String |
| 05 | Course Schedule | MEDIUM | 85.6 | 49% | Depth-First Search · Breadth-First Search · Graph |
| 06 | Shortest Word Distance | EASY | 85.6 | 66% | Array · String |
| 07 | Heaters | MEDIUM | 82.5 | 40% | Array · Two Pointers · Binary Search |
| 08 | Daily Temperatures | MEDIUM | 82.5 | 67% | Array · Stack · Monotonic Stack |
| 09 | Find Median from Data Stream | HARD | 79.0 | 53% | Two Pointers · Design · Sorting |
| 10 | Course Schedule II | MEDIUM | 79.0 | 53% | Depth-First Search · Breadth-First Search · Graph |
| 11 | Search Suggestions System | MEDIUM | 74.8 | 65% | Array · String · Binary Search |
| 12 | Making A Large Island | HARD | 69.7 | 55% | Array · Depth-First Search · Breadth-First Search |
| 13 | Merge Intervals | MEDIUM | 69.7 | 49% | Array · Sorting |
| 14 | Merge k Sorted Lists | HARD | 63.2 | 57% | Linked List · Divide and Conquer · Heap (Priority Queue) |
| 15 | Flip Equivalent Binary Trees | MEDIUM | 63.2 | 70% | Tree · Depth-First Search · Binary Tree |
| 16 | Flatten Binary Tree to Linked List | MEDIUM | 63.2 | 69% | Linked List · Stack · Tree |
| 17 | Shortest Word Distance II | MEDIUM | 63.2 | 62% | Array · Hash Table · Two Pointers |
| 18 | Basic Calculator II | MEDIUM | 63.2 | 46% | Math · String · Stack |
| 19 | Number of Distinct Islands | MEDIUM | 53.9 | 62% | Hash Table · Depth-First Search · Breadth-First Search |
| 20 | Race Car | HARD | 53.9 | 44% | Dynamic Programming |
| 21 | Time Based Key-Value Store | MEDIUM | 53.9 | 49% | Hash Table · String · Binary Search |
| 22 | Spiral Matrix | MEDIUM | 53.9 | 54% | Array · Matrix · Simulation |
| 23 | Minesweeper | MEDIUM | 53.9 | 68% | Array · Depth-First Search · Breadth-First Search |
| 24 | Snakes and Ladders | MEDIUM | 53.9 | 48% | Array · Breadth-First Search · Matrix |
| 25 | Move Zeroes | EASY | 53.9 | 63% | Array · Two Pointers |
| 26 | Search in Rotated Sorted Array | MEDIUM | 53.9 | 43% | Array · Binary Search |
| 27 | Basic Calculator | HARD | 53.9 | 46% | Math · String · Stack |
| 28 | Game of Life | MEDIUM | 53.9 | 71% | Array · Matrix · Simulation |
| 29 | Find the Duplicate Number | MEDIUM | 53.9 | 63% | Array · Two Pointers · Binary Search |
| 30 | Valid Parentheses | EASY | 53.9 | 42% | String · Stack |
| 31 | Rotting Oranges | MEDIUM | 53.9 | 57% | Array · Breadth-First Search · Matrix |
| 32 | Insert into a Sorted Circular Linked List | MEDIUM | 53.9 | 38% | Linked List |
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 Anduril 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- array19 · 59%
- depth first search8 · 25%
- breadth first search8 · 25%
- string8 · 25%
- matrix7 · 22%
- sorting6 · 19%
- two pointers5 · 16%
- binary search5 · 16%
- stack5 · 16%
- hash table4 · 13%
Array problems are the backbone here, accounting for nearly 60% of the reported difficulty. String and matrix manipulation follow, but the critical insight is that array problems almost always layer in another topic. Number of Islands, Making A Large Island, and Merge Intervals all require you to see the array through a different lens (graph search, union-find, sorting). DFS and BFS each appear in 8 problems and almost always together on the same problem. Two-pointers and binary-search cluster around sorting and interval problems. Stack shows up in monotonic-stack patterns like Daily Temperatures. Hash-table is lower-frequency but usually the constraint that forces your solution. Hard problems expect you to combine patterns fast. That's where StealthCoder becomes your hedge: if you're halfway through Merge k Sorted Lists or Find Median from Data Stream and the approach fragments, you get a working backup without the proctor knowing.
Companies with similar patterns
If you prepped for Anduril, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Anduril.
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.
Anduril interview FAQ
Should I study graph problems before arrays for Anduril?+
No. Arrays dominate with 19 occurrences. Learn array fundamentals and interval merging first. DFS/BFS patterns stack on top of array/matrix foundations. You'll see both together in problems like Number of Islands, but you need the base solid.
How important is union-find for this assessment?+
Moderate priority. Union-find appears in 3 problems, but two of them are hard (Number of Islands, Making A Large Island). It's a faster alternative to DFS for connected-components. Drill it after mastering DFS/BFS traversal on matrices.
Is binary-search worth studying if I know two-pointers?+
Yes, separately. Both appear 5 times, often in different contexts. Heaters and Search Suggestions System use binary-search for range queries. Two-pointers solves Merge Intervals and interval overlap. Know both patterns.
What's the toughest pattern I'll face?+
Hard problems combine multiple strategies. Merge k Sorted Lists requires heap design and merge-sort thinking. Find Median from Data Stream demands streaming design. Study design patterns under load, not just algorithm variants.
How many medium problems should I solve before the assessment?+
Anduril's test is 72% medium. Solve at least 15 to 20 distinct medium problems covering arrays, strings, sorting, and graph patterns. Focus on the problems listed here first, then generalize.