Arista Networks coding interview
questions, leaked.
38 problems reported across recent Arista Networks interviews. Top patterns: array, hash table, depth first search. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
Arista Networks interview assessments lean on arrays and hash tables, with a sharp pivot to linked-list manipulation and tree traversal. Of 38 reported problems, 12 are easy, 24 medium, and 2 hard. You'll see array problems like Find the Town Judge and Contains Duplicate II early, but the interview stacks medium-difficulty linked-list challenges like Reverse Nodes in k-Group and LRU Cache. These aren't trick questions. They're testing whether you can code under pressure. StealthCoder runs invisibly during your assessment, solving whatever pattern you freeze on in real time, so you don't tank a solvable problem mid-interview.
Top problems at Arista Networks
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Restore IP Addresses | MEDIUM | 100.0 | 53% | String · Backtracking |
| 02 | Construct String With Repeat Limit | MEDIUM | 100.0 | 71% | Hash Table · String · Greedy |
| 03 | Find the Town Judge | EASY | 97.6 | 50% | Array · Hash Table · Graph |
| 04 | Reverse Nodes in k-Group | HARD | 94.9 | 63% | Linked List · Recursion |
| 05 | Reverse Linked List II | MEDIUM | 94.9 | 50% | Linked List |
| 06 | Reorder List | MEDIUM | 88.6 | 63% | Linked List · Two Pointers · Stack |
| 07 | Contains Duplicate II | EASY | 80.2 | 49% | Array · Hash Table · Sliding Window |
| 08 | Inorder Successor in BST II | MEDIUM | 80.2 | 61% | Tree · Binary Search Tree · Binary Tree |
| 09 | Rotated Digits | MEDIUM | 80.2 | 56% | Math · Dynamic Programming |
| 10 | Search in Rotated Sorted Array | MEDIUM | 74.5 | 43% | Array · Binary Search |
| 11 | Inorder Successor in BST | MEDIUM | 74.5 | 51% | Tree · Depth-First Search · Binary Search Tree |
| 12 | LRU Cache | MEDIUM | 74.5 | 45% | Hash Table · Linked List · Design |
| 13 | Remove Linked List Elements | EASY | 74.5 | 52% | Linked List · Recursion |
| 14 | Maximum Depth of Binary Tree | EASY | 67.3 | 77% | Tree · Depth-First Search · Breadth-First Search |
| 15 | Merge Two Sorted Lists | EASY | 67.3 | 67% | Linked List · Recursion |
| 16 | Maximum Units on a Truck | EASY | 67.3 | 74% | Array · Greedy · Sorting |
| 17 | Missing Element in Sorted Array | MEDIUM | 67.3 | 59% | Array · Binary Search |
| 18 | Moving Average from Data Stream | EASY | 67.3 | 80% | Array · Design · Queue |
| 19 | Missing Number | EASY | 67.3 | 70% | Array · Hash Table · Math |
| 20 | Binary Tree Maximum Path Sum | HARD | 67.3 | 41% | Dynamic Programming · Tree · Depth-First Search |
| 21 | Course Schedule II | MEDIUM | 67.3 | 53% | Depth-First Search · Breadth-First Search · Graph |
| 22 | Word Search | MEDIUM | 57.2 | 45% | Array · String · Backtracking |
| 23 | Implement Trie (Prefix Tree) | MEDIUM | 57.2 | 68% | Hash Table · String · Design |
| 24 | Kth Largest Element in a Stream | EASY | 57.2 | 60% | Tree · Design · Binary Search Tree |
| 25 | Best Time to Buy and Sell Stock | EASY | 57.2 | 55% | Array · Dynamic Programming |
| 26 | Merge In Between Linked Lists | MEDIUM | 57.2 | 82% | Linked List |
| 27 | Find the Winner of the Circular Game | MEDIUM | 57.2 | 82% | Array · Math · Recursion |
| 28 | Validate Binary Search Tree | MEDIUM | 57.2 | 34% | Tree · Depth-First Search · Binary Search Tree |
| 29 | Palindromic Substrings | MEDIUM | 57.2 | 72% | Two Pointers · String · Dynamic Programming |
| 30 | Flatten a Multilevel Doubly Linked List | MEDIUM | 57.2 | 61% | Linked List · Depth-First Search · Doubly-Linked List |
| 31 | Search a 2D Matrix | MEDIUM | 57.2 | 52% | Array · Binary Search · Matrix |
| 32 | Kth Missing Positive Number | EASY | 57.2 | 62% | Array · Binary Search |
| 33 | Path Sum II | MEDIUM | 57.2 | 60% | Backtracking · Tree · Depth-First Search |
| 34 | Integer to Roman | MEDIUM | 57.2 | 69% | Hash Table · Math · String |
| 35 | Top K Frequent Elements | MEDIUM | 57.2 | 65% | Array · Hash Table · Divide and Conquer |
| 36 | Longest Common Subsequence | MEDIUM | 57.2 | 58% | String · Dynamic Programming |
| 37 | Remove All Occurrences of a Substring | MEDIUM | 57.2 | 78% | String · Stack · Simulation |
| 38 | Contains Duplicate | EASY | 57.2 | 63% | Array · Hash Table · Sorting |
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 Arista Networks OA. The proctor cannot see it. Screen share cannot detect it. Built by an engineer who got tired of watching his cohort grind for six months and still get filtered at the OA stage.
Get StealthCoder- array14 · 37%
- hash table9 · 24%
- depth first search8 · 21%
- linked list8 · 21%
- string8 · 21%
- tree7 · 18%
- binary tree7 · 18%
- binary search5 · 13%
- recursion5 · 13%
- dynamic programming5 · 13%
Arrays dominate the surface (14 problems), but hash tables (9) and depth-first search (8) are the true gatekeepers. Linked-list problems (8) are a major chunk and tend to be medium-weight. Once you hit a linked-list manipulation problem, reversals and pointer rewiring matter. Trees (7 problems total, split between binary-tree and BST variants) require solid DFS instinct. The difficulty split is forgiving: 12 easy problems means you'll get confidence wins early. But the 24 medium problems are where candidates actually fail. LRU Cache, Reverse Nodes in k-Group, and Reorder List are the types that sound familiar but require careful pointer logic under time pressure. That's where StealthCoder becomes your safety net. If you blank on the pointer transitions mid-interview, invisible backup solves it in seconds. Dynamic programming (5 problems) and binary search (5 problems) are lower frequency but still appear enough to sting if you haven't drilled them.
Companies with similar patterns
If you prepped for Arista Networks, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass Arista Networks.
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 engineer who got tired of watching his cohort grind for six months and still get filtered at the OA stage. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Arista Networks interview FAQ
Should I spend most of my prep time on arrays or linked lists for Arista?+
Arrays come first (14 problems), but don't stop there. Linked-list problems are medium-difficulty and cluster together. Once you're solid on hash-table pairs and sliding-window array patterns, pivot to linked-list pointer manipulation. LRU Cache and Reverse Nodes in k-Group are the ones that separate passed from rejected.
How many tree and DFS problems should I expect?+
Trees show up in 7 problems, and depth-first search in 8. They're not the bulk, but they're frequent enough that weak DFS means you'll hit at least one you can't finish. Maximum Depth of Binary Tree is easy, but Inorder Successor in BST variants are medium. Get comfortable with both before your interview.
Is dynamic programming a major focus for Arista?+
No. Only 5 problems in the dataset involve DP, compared to 14 array problems. Don't let DP consume your week. Drill arrays, hash tables, and linked lists first. DP is your hedge if you have extra time, not your core focus.
What's the hardest problem type I should prepare for?+
Only 2 hard problems reported, but both are linked-list related (Reverse Nodes in k-Group). Hard doesn't necessarily mean you'll see it, but if you do, it's a pointer-manipulation problem under time pressure. Know your linked-list reversal patterns cold.
Is the easy-to-medium split forgiving enough to wing it?+
12 easy problems give you early confidence, but 24 medium means two-thirds of your assessment is teeth. Easy problems are warm-up. You'll need solid medium-difficulty solutions on hash tables, linked lists, and trees to pass. Don't assume easy early wins guarantee a pass.