Arista Networks, Eos team interview
Question Details
Hi all, I have an upcoming interview with Arista Networks (EOS team) for a Systems Software Engineer role with around 4 years of experience, and I have about one week to prepare. From what I understan
Full Details
Hi all, I have an upcoming interview with Arista Networks (EOS team) for a Systems Software Engineer role with around 4 years of experience, and I have about one week to prepare. From what I understand, the first round can either be a DSA-style coding problem (arrays, linked lists, trees, etc.) or a partially implemented/buggy code module where we need to debug, complete functions, and possibly write unit tests. I’m trying to get a clearer picture of what to expect in reality. For candidates with \~4 YOE, is the round more focused on DSA or on debugging and code comprehension? Also, how deeply should I prepare topics like binary trees, BSTs, linked lists, and LRU cache? I’d also like to understand how important C/C++ internals are for this round—things like pointers, memory issues, and edge-case handling. Do they expect writing unit tests during the interview as well? Given that I only have about 7 days, any advice on which topics to prioritize or how to structure preparation would be really helpful. Thanks in advance! PS - Used AI for better wording
About This Question
This is a reported interview question from a arista interview for a swe role during the onsite round reported in 2026.
It covers the following topics: Arrays, Binary Tree, Linked List .
Topics
About Arista Interview Reports
This question was reported by a candidate who interviewed at Arista. LeakCode aggregates interview reports from 10+ sources, including 1Point3Acres, Glassdoor, LeetCode Discuss, Blind, Reddit, Indeed, and Nowcoder. Each report is translated where necessary, deduplicated against existing entries, and tagged by company, role, round type, and reporting date.
Use this question as one calibration data point, not a memorization target. Companies typically rotate their question pools every 2-4 months; the exact wording of a 2024 question may differ from what you encounter today. The underlying pattern, difficulty level, and follow-up depth at Arista are the higher-signal extractions to take from this report.
For broader preparation context, the Arista interview process typically includes a recruiter screen, one or two technical phone screens, and a 4-5 round on-site loop covering coding, system design (at L4+ levels), and behavioral. Reports tagged on LeakCode show the round-by-round distribution and typical difficulty calibration. To browse questions filtered by round type and seniority, use the company hub linked above.
How To Practice This Type of Question
Solve similar problems on LeetCode under timed conditions (25-35 minutes per medium difficulty). The goal is pattern recognition: recognize the underlying technique (sliding window, two-pointer, BFS, memoized recursion, etc.) within 60-90 seconds of reading. Strong candidates verbalize their hypothesis out loud before coding, then iterate based on feedback. Weak candidates dive into implementation immediately, lose time on the wrong approach, and run out of time for follow-ups.
Companies update their question pools every 2-4 months. The exact wording of any given question may have been retired by the time you interview. Focus your prep on the pattern, not the specific problem. The patterns that appear in Arista reports consistently are the ones worth investing in; one-off niche problems are not.
During Your Arista Round
Apply the standard interview round template: clarify requirements (2-3 minutes), state your approach out loud and confirm direction with the interviewer (3-5 minutes), code with narration (15-25 minutes), test with concrete examples including edge cases (5 minutes), discuss optimization or trade-offs if time permits (5 minutes). This template is universally accepted across FAANG and adjacent companies; deviating from it produces weaker interviewer feedback signal.
The single most predictive failure mode in Arista reports tagged "no hire": not asking clarifying questions. Interviewers are explicitly trained to weight this. Strong candidates ask 3-5 clarifying questions even on problems that look obvious; weak candidates dive into code immediately. The clarifying-question check is often the first signal recorded in the interviewer's written notes.