Amazon SDE Intern Interview Experience — SDE Intern
Summary
I completed two on‑site rounds for an Amazon SDE Intern position, solving a monotonic‑stack problem and a min‑heap scheduling problem, and received an offer.
Full Experience
Amazon SDE Intern Interview Experience — SDE Intern
Sharing my recent Amazon SDE Intern interview experience in the hope that it helps other candidates prepare.
Final verdict: Selected
Format: Both rounds were face-to-face, and I had to write the code on paper without an IDE/compiler.
Round 1
Remove K Digits
The question was to remove k digits from a number represented as a string to make the resulting number as small as possible.
LeetCode: LC 402 – Remove K Digits
Pattern: Monotonic Stack
Round 2
1. Minimum Machines Required for Jobs
I was given multiple jobs with start and end times and had to find the minimum number of machines required. A machine could be reused as soon as it became free.
Example:
Job 1: 1 → 5
Job 2: 5 → 8
Both can use the same machine.
I initially suggested a binary search approach, which was incorrect. The interviewer gave me a hint, after which I arrived at the Min Heap approach and solved it.
There were no predefined test cases. When I asked for one, the interviewer asked me to create my own test cases and explain why the answers were correct.
Closest LeetCode problem: LC 253 – Meeting Rooms II
Pattern: Sorting + Min Heap
2. Next Smaller Ticket Price
Instead of temperatures, I was given ticket prices and had to find the next smaller price for each ticket.
Example:
Prices: [8, 4, 6, 2, 3]
Answer: [4, 2, 2, -1, -1]
This was essentially the Daily Temperatures pattern with a small modification.
LeetCode: LC 739 – Daily Temperatures
Pattern: Monotonic Stack / Next Smaller Element
Preparation Tips
I would recommend preparing:
- Monotonic Stack — Next Greater/Smaller, Daily Temperatures, Remove K Digits
- Min Heap / Priority Queue — Scheduling and resource allocation
- Intervals
- Writing code on paper
- Creating and explaining your own test cases
Overall, it was a great learning experience. I initially went in the wrong direction on the machine problem, but with the interviewer’s hint, I was able to reach the correct approach.
Thankfully, the final result was positive — I was selected for the Amazon SDE Intern role.
Hope this helps other candidates preparing. All the best!
Interview Questions (3)
Remove K Digits
Given a non‑negative integer num represented as a string, remove exactly k digits from the number so that the new number is the smallest possible. The resulting number should not contain leading zeros.
Minimum Machines Required for Jobs
Given a list of jobs, each with a start time and an end time, determine the minimum number of machines needed so that each job can be processed. A machine becomes available again as soon as its current job finishes.
Example:
Job 1: 1 → 5
Job 2: 5 → 8 (can reuse the same machine)
Next Smaller Ticket Price
Given an array of ticket prices, for each price find the next price to its right that is smaller. If no such price exists, return -1.
Example:
Prices: [8, 4, 6, 2, 3]
Answer: [4, 2, 2, -1, -1]
Preparation Tips
Recommended topics:
- Monotonic Stack — Next Greater/Smaller, Daily Temperatures, Remove K Digits
- Min Heap / Priority Queue — Scheduling and resource allocation
- Intervals
- Writing code on paper
- Creating and explaining your own test cases