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Arista Networks

Large Enterprises

Arista Networks is an American computer networking company that designs and sells high-performance data center and cloud networking switches and software. It is known for its cloud-grade Ethernet switches and its EOS (Extensible Operating System) network operating system, serving hyperscale data centers, enterprises, and service providers.

4 interview notes · updated Jul 2026

Arista Networks·Software Engineer·Technical Phone Screen

Jul 2026
Interviewed for a software engineer role at Arista Networks and got a linked list problem that looked easy on the surface but had enough edge cases to trip you up if you weren't careful about how you handled the head pointer.
  • Given the head of a singly linked list and an integer target, remove all nodes with that value and return the new head. The target can appear at the head, middle, or tail any number of times.

“My first instinct was to just walk the list and splice out matching nodes, which works fine for the middle and tail.”

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Arista Networks·Software Engineer·Technical Phone Screen

Jun 2026
Arista Networks SWE interview with a debugging-focused question that had a pretty nasty follow-up. The main question was manageable but the follow-up is where things got interesting.
  • You're given a buggy code snippet where the root cause is an out-of-bounds memory access. Find the bug and explain how to fix it.
  • The out-of-bounds write doesn't cause a segfault here, it causes an infinite loop instead. Why?

“Pretty standard debugging exercise on the surface.”

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Arista Networks·Software Engineer·Technical Phone Screen

May 2026
Arista Networks coding round, one algorithm question that looks simple but has a sneaky twist. Worth reviewing the classic missing number problem before you go in, because they specifically push you past the easy version.
  • Given a sorted array that contains all integers in some range [L, R] except one, find the missing number. Be prepared to discuss multiple approaches and their tradeoffs.

“I jumped straight to Gauss summation and got it working, sum of L to R minus the actual array sum gives you the answer, O(n) time O(1) space.”

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Arista Networks·Software Engineer·Technical Phone Screen

Apr 2026
Coding round at Arista Networks for a software engineer position. Pretty standard stuff, one algorithm question with a follow-up on complexity. Nothing too wild but they did push on edge cases more than I expected.
  • Write a function to check if a string is a palindrome. Make sure to handle empty strings and null input, then walk through the time and space complexity of your solution.

“I jumped straight into the logic and forgot about null for an embarrassingly long time.”

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