Meta coding interview
questions, leaked.
217 problems reported across recent Meta interviews. Top patterns: array, string, hash table. The list below is what most candidates actually saw, plus the honest play if you can't grind all of it.
Meta asks 217 problems across their interview loop, and you're looking at a dataset skewed hard toward arrays (109 problems) and strings (54). The difficulty split is brutal: 61% medium, 24% easy, 15% hard. You've got maybe a week to cram the patterns that actually show up. Arrays and two-pointers dominate the easy tier, but the mediums are where they separate signal from noise: tree traversals, hash-table lookups, dynamic programming. If you blank mid-assessment, StealthCoder runs invisible behind the screen and surfaces a working solution in seconds, no proctor visibility. Your job before the OA is to be bulletproof on the patterns below, and let the tool be your backup.
Top problems at Meta
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Minimum Remove to Make Valid Parentheses | MEDIUM | 0.0 | 71% | String · Stack |
| 02 | Valid Word Abbreviation | EASY | 0.0 | 37% | Two Pointers · String |
| 03 | Binary Tree Vertical Order Traversal | MEDIUM | 0.0 | 57% | Hash Table · Tree · Depth-First Search |
| 04 | Valid Palindrome II | EASY | 0.0 | 43% | Two Pointers · String · Greedy |
| 05 | Lowest Common Ancestor of a Binary Tree III | MEDIUM | 0.0 | 82% | Hash Table · Two Pointers · Tree |
| 06 | Merge Sorted Array | EASY | 88.1 | 53% | Array · Two Pointers · Sorting |
| 07 | Kth Largest Element in an Array | MEDIUM | 0.0 | 68% | Array · Divide and Conquer · Sorting |
| 08 | Pow(x, n) | MEDIUM | 86.9 | 37% | Math · Recursion |
| 09 | Binary Tree Right Side View | MEDIUM | 0.0 | 67% | Tree · Depth-First Search · Breadth-First Search |
| 10 | Simplify Path | MEDIUM | 85.9 | 48% | String · Stack |
| 11 | Merge Intervals | MEDIUM | 84.8 | 49% | Array · Sorting |
| 12 | Basic Calculator II | MEDIUM | 0.0 | 46% | Math · String · Stack |
| 13 | Two Sum | EASY | 83.8 | 56% | Array · Hash Table |
| 14 | Lowest Common Ancestor of a Binary Tree | MEDIUM | 0.0 | 67% | Tree · Depth-First Search · Binary Tree |
| 15 | Find Peak Element | MEDIUM | 0.0 | 47% | Array · Binary Search |
| 16 | Nested List Weight Sum | MEDIUM | 0.0 | 86% | Depth-First Search · Breadth-First Search |
| 17 | Random Pick with Weight | MEDIUM | 0.0 | 48% | Array · Math · Binary Search |
| 18 | Sum Root to Leaf Numbers | MEDIUM | 0.0 | 69% | Tree · Depth-First Search · Binary Tree |
| 19 | Diameter of Binary Tree | EASY | 0.0 | 64% | Tree · Depth-First Search · Binary Tree |
| 20 | Next Permutation | MEDIUM | 78.3 | 43% | Array · Two Pointers |
| 21 | Top K Frequent Elements | MEDIUM | 0.0 | 65% | Array · Hash Table · Divide and Conquer |
| 22 | Merge k Sorted Lists | HARD | 77.2 | 57% | Linked List · Divide and Conquer · Heap (Priority Queue) |
| 23 | 3Sum | MEDIUM | 76.7 | 37% | Array · Two Pointers · Sorting |
| 24 | Best Time to Buy and Sell Stock | EASY | 0.0 | 55% | Array · Dynamic Programming |
| 25 | Buildings With an Ocean View | MEDIUM | 0.0 | 81% | Array · Stack · Monotonic Stack |
| 26 | Custom Sort String | MEDIUM | 0.0 | 72% | Hash Table · String · Sorting |
| 27 | Find First and Last Position of Element in Sorted Array | MEDIUM | 72.1 | 47% | Array · Binary Search |
| 28 | K Closest Points to Origin | MEDIUM | 0.0 | 68% | Array · Math · Divide and Conquer |
| 29 | Clone Graph | MEDIUM | 0.0 | 62% | Hash Table · Depth-First Search · Breadth-First Search |
| 30 | Subarray Sum Equals K | MEDIUM | 0.0 | 45% | Array · Hash Table · Prefix Sum |
| 31 | Valid Parentheses | EASY | 71.1 | 42% | String · Stack |
| 32 | Valid Number | HARD | 70.2 | 22% | String |
| 33 | Range Sum of BST | EASY | 0.0 | 87% | Tree · Depth-First Search · Binary Search Tree |
| 34 | Dot Product of Two Sparse Vectors | MEDIUM | 0.0 | 90% | Array · Hash Table · Two Pointers |
| 35 | Valid Palindrome | EASY | 0.0 | 51% | Two Pointers · String |
| 36 | Minimum Window Substring | HARD | 68.6 | 45% | Hash Table · String · Sliding Window |
| 37 | Shortest Path in Binary Matrix | MEDIUM | 0.0 | 50% | Array · Breadth-First Search · Matrix |
| 38 | Copy List with Random Pointer | MEDIUM | 0.0 | 61% | Hash Table · Linked List |
| 39 | Longest Common Prefix | EASY | 66.7 | 45% | String · Trie |
| 40 | Add Two Numbers | MEDIUM | 65.1 | 46% | Linked List · Math · Recursion |
| 41 | Sliding Window Median | HARD | 0.0 | 39% | Array · Hash Table · Sliding Window |
| 42 | Making A Large Island | HARD | 0.0 | 55% | Array · Depth-First Search · Breadth-First Search |
| 43 | Subsets | MEDIUM | 64.1 | 81% | Array · Backtracking · Bit Manipulation |
| 44 | Letter Combinations of a Phone Number | MEDIUM | 64.1 | 64% | Hash Table · String · Backtracking |
| 45 | Remove Nth Node From End of List | MEDIUM | 63.6 | 49% | Linked List · Two Pointers |
| 46 | Longest Substring Without Repeating Characters | MEDIUM | 63.1 | 37% | Hash Table · String · Sliding Window |
| 47 | Accounts Merge | MEDIUM | 0.0 | 60% | Array · Hash Table · String |
| 48 | LRU Cache | MEDIUM | 0.0 | 45% | Hash Table · Linked List · Design |
| 49 | Max Consecutive Ones III | MEDIUM | 0.0 | 66% | Array · Binary Search · Sliding Window |
| 50 | Trapping Rain Water | HARD | 60.6 | 65% | Array · Two Pointers · 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 Meta 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- array109 · 50%
- string54 · 25%
- hash table39 · 18%
- depth first search35 · 16%
- two pointers33 · 15%
- tree33 · 15%
- binary tree33 · 15%
- dynamic programming29 · 13%
- breadth first search27 · 12%
- math26 · 12%
Array problems own the Meta pipeline: they're 50% of the reported surface area. String comes second at 25%, then hash-table, tree work, and search algorithms all cluster around 15-20%. The top problems reveal the true shape of their interviews: Minimum Remove to Make Valid Parentheses, Binary Tree Vertical Order Traversal, Lowest Common Ancestor, Merge Intervals, Basic Calculator II. These aren't one-liners. They're multi-step, require pattern recognition, and sit squarely in the medium band. Two-pointers and depth-first search appear in roughly 15% of problems each, so knowing when to apply them matters more than drilling 200 variants. The hard problems (33 total, 15% of the set) are outliers unless you're targeting a senior or specialized team. Your pre-OA prep should front-load arrays and strings, then anchor on tree traversals and hash-table design. If you hit a medium you've never seen during the live assessment, StealthCoder solves it in real time without the proctor catching the lag.
Companies with similar patterns
If you prepped for Meta, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Meta.
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.
Meta interview FAQ
How many array problems should I solve before the Meta OA?+
109 of 217 problems involve arrays, so treat it as your primary surface. Aim to solve 20-25 distinct array patterns (two-pointers, sliding window, merge, partition). The top problems like Merge Intervals and Merge Sorted Array are direct hits. Quality beats quantity; understand the intent, not memorization.
Is string manipulation weighted as heavily as arrays?+
No. Strings appear in 54 problems (25%), roughly half array frequency. Focus on stack-based string problems (Minimum Remove to Make Valid Parentheses), palindrome validation, and basic parsing. They're often combined with other topics, not standalone.
Do I need to master dynamic programming for Meta?+
It appears in 29 problems (13%), so it's present but not dominant. If you're aiming for mid to senior levels, spend time on it after arrays and trees. Easy to medium DP problems are fair game; don't obsess over the hardest variants unless you have time.
Should I drill tree problems before hash-table?+
Both are roughly equal in frequency (33 tree, 39 hash-table). Start with hash-table basics (Two Sum, design patterns) since they're simpler and build intuition faster. Tree work (DFS, BFS, LCA) comes next and often combines with hash-tables, so the order matters.
What's the distribution of easy vs medium problems I'll face?+
Expect 24% easy, 61% medium, 15% hard. The easy problems are warm-ups (Merge Sorted Array, Valid Palindrome II); don't waste OA time on them. Mediums are the filter. If you skip prep and hit an unfamiliar medium during screen share, StealthCoder is your safety net.