Interview Experience | Amazon | SDE 2 | 3 YoE | REJECT
Summary
I went through three interview rounds, solving tree distance and stack design problems, a Basic Calculator LeetCode question, and a system design discussion, but was ultimately rejected.
Full Experience
I don't remember the OA DSA problem, the second one was a "dev" based where some remote ide was given access to via hackerrank. I was able to use AI in the side bar, like cursor. It was for role based in Hyd / Blr. The interviewer in R2 was abroad based.
Round 1
- Find distance between any two nodes in a tree. Parent pointers not given. Only have root, source, and target in input.
- Designing a stack that supports push, pop, get middle, get top in O(1) time.
- LPs
Was able to solve first question completely and second one's core logic without complete impl. I implemented get middle post basic DS decision
Round 2
- LPs
- Basic Calculator - https://leetcode.com/problems/basic-calculator/description/
- Extending this soln in an object oriented manner
Interviewer said that I was too close to the original solution
Round 3
- Told about myself for first 5-7 mins.
- Probed real hard upon why I wanted to switch (I already had made 1 switch and was looking for second)
- He started then with the best thing you've worked upon in your past org.
- Kinda felt like stepping into the NDA territory, still explained things properly. Asked a couple of questions on the way like why you folks used X or Y
- At the end he asked one question only(yes, only 1): how would you include this new feature as well in this design?
- I proposed 2 solns, he asked me to write down pros and cons for both
- Properly articulated and wrote them for both (min 3-3 for both)
- Asked me if I had any questions to ask him.
Got rejected. Recruiter told me feedback from 2 and 3 was negative. No specifics despite asking explicitly.
Hope this helps!
Interview Questions (3)
Find distance between two nodes in a tree (no parent pointers)
Given the root of a binary tree and two nodes identified as source and target, compute the distance (number of edges) between the source and target nodes. Parent pointers are not provided; only the tree structure rooted at the given node is available.
Design a stack with O(1) push, pop, getTop, and getMiddle
Create a stack data structure that supports the following operations in O(1) time:
- push(x): Insert element x on top of the stack.
- pop(): Remove and return the top element.
- getTop(): Return the top element without removing it.
- getMiddle(): Return the middle element of the stack. The implementation must maintain constant‑time access to the middle element as the stack size changes.
Basic Calculator
Implement a basic calculator to evaluate a string expression containing non‑negative integers, '+', '-', '(', ')', and whitespace. The expression follows standard arithmetic rules and may include nested parentheses.