Amazon SDE Intern OA + Interview Detailed Experience
Summary
I completed an online assessment followed by two interview rounds for an SDE Intern position. The OA was relatively easy and I was able to solve both problems; the interview rounds covered standard DSA, a behavioral question and GenAI topics.
Full Experience
Online Assessment
Time Limit: 70 minutes, 2 questions.
Question 1: There are N tasks with capacities cap[i] and M workers with throughput[j]. A worker can take a task if cap[i] ≤ throughput[j]. One worker handles one task per second and then needs a 1‑second buffer. Return the total time to finish all tasks or -1 if impossible.
My Approach: Sort tasks and workers descending, use a min‑heap to track available workers and assign the hardest tasks first.
Question 2: There are N servers with capacities cap[i]. Floor(N/2) servers must be primary and the rest secondary; each primary needs a secondary with capacity ≥ primary. Maximize the sum of primary capacities.
My Approach: Sort descending and sum capacities at odd indices (1‑based) as primaries.
Overall, the OA felt easy and took about 25 minutes.
Interview Round 1
Consisted of 2 DSA questions, 1 behavioral (LP) question and 2 GenAI related questions.
Question 1: Longest Common Subsequence (LeetCode). Explained brute‑force then optimal DP and implemented it.
Question 2: Merge Two Sorted Linked Lists (LeetCode). Described two‑pointer approach and coded it.
LP: "Tell me a time when you worked on a difficult problem" – discussed a hackathon RL reward‑hacking project.
GenAI: Discussed daily usage and a project building an AI associate for VCs.
Overall, the interviewers were satisfied.
Interview Round 2
Consisted of 2 DSA questions, resume discussion and 1 LP question.
Question 1: Given an array, repeatedly merge two adjacent equal numbers into their sum. Return the smallest possible final array. Used a stack‑based solution after a failed two‑pointer attempt.
Question 2: Kth Smallest Element in a Sorted Matrix (LeetCode). Started with brute‑force, moved to a min‑heap BFS approach, then to a binary‑search counting method after a hint.
LP: "Tell me a time when you noticed a critical bug yourself" – shared an internship story.
The interview concluded positively.
Decision pending; I await the outcome.
Interview Questions (6)
Task Assignment with Capacity and Throughput
N tasks, cap[i] denotes the capacity needed to complete i‑th task. M workers, throughput[j] denotes the maximum capacity, i.e. j‑th worker can take i‑th task if cap[i] <= throughput[j]. One worker can take only one task, one task will take 1 second to finish, and after finishing a task a worker needs a buffer of 1 second before picking another task. Return the total time needed to complete all tasks, if not possible return -1.
Maximize System Power with Primary and Secondary Servers
N servers, cap[i] represents the capacity of the i‑th server. floor(N/2) servers need to be primary, and the rest secondary, each primary server needs its own secondary server, each secondary server must be greater than or equal to its primary server in terms of capacity. The power of the system is determined by the summation of the capacities of the primary servers. Return the maximum possible power of the system, if we allocate primary and secondary servers optimally.
Longest Common Subsequence
Given two strings, find the length of their longest common subsequence.
Merge Two Sorted Linked Lists
Merge two sorted singly‑linked lists and return it as a sorted list. The new list should be made by splicing together the nodes of the first two lists.
Merge Adjacent Equal Numbers to Minimize Array
Given an array, you can repeatedly merge (or sum) two adjacent equal numbers, remove both numbers, and replace them with the new merged number. You may perform this operation any number of times. Return the smallest possible final array after applying the operations optimally. Example: [3,1,1] becomes [3,2]; for [1,1,1,1] the optimal final array is [4] not [1,2,1].
Kth Smallest Element in a Sorted Matrix
Given an n x n matrix where each row and each column is sorted in ascending order, find the k‑th smallest element in the matrix.