Arista Networks

Arista Networks Interviews

1. Sep 12, 2023

   Software Engineer Interview

   Anonymous Employee in Vancouver, BC

   No Offer

   Negative Experience

   Average Interview

   Application

   I applied online. I interviewed at Arista Networks (Vancouver, BC) in Sep 2023

   Interview

   First call with recruiter 30 mins. Scheduled phone screen with an engineer 1h. Using the Coderpad platform. The first interview was easy and the interviewer was very professional and nice. They cared about the thinking process and pointed you in the correct direction for minor mistakes. Started with short questions from the resume, longer questions about C low-level, printf function expected output, and then leetcode questions about finding missing numbers in sorted arrays and then BST in order successor variations. The final interviews were two 1h sessions scheduled for next week. This was one of the worst interview experiences I've had so far. The interviewer did not set up the environment beforehand and asked questions about my resume to fill in the gap while setting up the coderpad while clearly not listening to my answers. The question was to design Stack API and requirements are not given. I started with exploratory questions about requirements: Homogenous/ Heterogenous Hold data vs. hold only pointers and the caller will handle the actual data allocation discussed tradeoffs. Describe two possible ways of implementation using dynamic arrays vs. linked lists and describe the tradeoff: For the dynamic array, it will have some memory overhead of empty cells which I said we can dynamically reallocate to adjust the size. For the linked list it has to call allocate/deallocate for each push/pop which is time-consuming and has an additional pointer to the next item (memory overhead). The interviewer kept interrupting the thought process by asking too many follow-up questions (for every sentence I told he asked one or two follow-up questions) and he laughed if the answer was wrong in his opinion. Example: What is the time complexity of push with the dynamic array? Answer: O(1) On average if we hit the capacity and need allocation it takes more time. He laughed and said how come reallocation can be O(1). He asked to quantify the time complexity of realloc() function which really depends on the system but I answered it can be constant time if there is a contiguous memory available on the heap or it can find another block and needs to copy which can take O(n). But still average TC of the stack is O(1) because only when we hit capacity we do reallocate (for the nth push) then we can double the capacity and so on. Anyways he said the linked list approach is better (15 mins left) but how can you remove pointer overhead?! I was really confused as a singly linked list without a pointer is not a linked list. Asked about the problem of holding pointers instead of copy of data what can you do to handle (answer using shared ptr). Then he stopped the interview at the 1h mark and asked me to think about the homogenous solution while he talks to the other interviewer. When he came back I answered the question correctly but he said Yeah that's right but the next interview is not gonna happen see you next time bye! Overall if I mentioned something wrong he pushed me in the wrong direction intentionally even when I tried to back up and correct it. It is not clear at all what they are trying to gauge with this interview he seemed to have a specific implementation in mind and just looked for that memorized answer.
   

   Interview

   Mentioned above! Design a Stack.

   1 Answers