Arista Networks

## Interview Experience ### Round 0: Written Round *Type:** Written Round **Part 1 - MCQ (15 Questions):** Topics included OS, Bash code output, and Algorithm-based questions (e.g., Heapify). **Part 2 - Coding (3 questions):** Q1: Easy-Medium (Queue) Q2: Medium (Based on prefix-sum) Q3: Medium-Hard (Greedy on Tree) *Performance:** Performed well in MCQs (according to the first interviewer). Passed approximately 30/45 test cases in the coding section. -- ### Round 1: Online Interview [1 hr 10 min] *Type:** Technical (OA Revisit + 2 DSA + OS Concepts) #### OA Revisit The interviewer mentioned that my performance in the coding section of the OA was not very strong and asked me to explain my approach for all three questions. I explained the optimal approach for Q1. He asked me to skip Q2 and explain Q3. Since he did not recall the specific question clearly, he provided an alternative Tree question to code. #### DSA Conducted on a shared code editor with driver code provided. **Q1: Check if the given linked list is a palindrome or not.** Approach: Provided brute-force followed by optimal [TC: O(n); SC: O(1)]. Task: Coded and tested on multiple test cases. **Q2: Check if the given Binary Tree is balanced or not.** Task: Coded and tested on multiple test cases. **Follow-up:** Check if it is a BST or not without storing elements in a vector. I explained the pseudocode and the interviewer was satisfied. #### OS & C Programming **Virtual Memory:** What is virtual memory? What are page faults? Given a scenario, I had to count the number of page faults using FIFO replacement. **Processes vs. Threads:** General differences. **Thread Execution:** Can the execution of one thread affect others? **Deadlocks:** What is a deadlock? What are the 4 conditions for deadlock? How can we prevent deadlocks? **General Concepts:** Discussed paging, synchronization mechanisms (mutex locks, semaphores). **C Code Output:** Predict the output of a given C code snippet to test knowledge of pre-decrement vs. post-decrement. *Closing:** I asked about the nature of work for an intern since I hadn't done a major Networks project. -- ### Round 2: Offline Interview [1 hr 50 min] *Type:** Technical (Resume + OS + CN + DSA) #### Resume Summarized my resume, focusing on a Web-Dev and a Recommendation Systems project. The interviewer noted that while the projects were impressive, they weren't closely related to the work at the company. I mentioned my experience as a Computer Networks Teaching Assistant (CN TA) to demonstrate my fit for the role. #### Computer Networks (CN) **DNS:** Explain the entire flow of searching for a website in a browser, including how DNS look-up works (Local, DNS, Auth DNS, TLD DNS, Root DNS servers). #### Operating Systems (OS) & Architecture **Architecture:** Difference between 32-bit and 64-bit architecture machines (Size of register). **Commands:** How to check if a machine is 32-bit or 64-bit (e.g., `arch` command). **Data Types:** Difference between `sizeof(int)` in 32-bit vs 64-bit architectures. (Answer: Same - 4 bytes; however, pointer size equals register size, so `sizeof(int*)` differs). **Compilers:** Difference between `sizeof(int)` in two different compilers. I estimated no difference. #### DSA Conducted on a shared code editor without driver code. **Q1: Create a BST from an unsorted vector.** Requirement: Take one element at a time. Ignore duplicates. Print inorder traversal to verify. Task: Coded and tested on multiple test cases. **Follow-up:** Find LCA of 2 nodes in a BST. I was specifically asked for a BST-specific approach rather than a general Binary Tree approach. Explained pseudocode on a whiteboard with dry-runs. *Closing:** Asked about work-life balance and growth trajectory. The interviewer provided detailed answers. -- ### Overall Experience **Interviewers:** Friendly and patient. The interviews were long but smooth. **Observations:** Resume content didn't seem to carry much weight for these specific interviewers. DBMS was not asked at all. **Areas to Focus On:** C programming (especially pointers), OS, Computer Networks. **DSA Topics:** Linked List, Trees (BT and BST), Trie. (Recommendation: Follow Striver’s A2Z).