SDE I at Amazon

How it went

What they would tell you

How to prepare

Their background

Round by round

1. 1

   Online Assessment (OA)60 min

   Problem 1: Change Case of Each Character in a String, i had to modify the case of each character in a string. Problem 2: Better Compression of String, a slight modification of the original problem with harder constraints. Leadership Principles Section, this part was harder than I expected

   • Change Case of Each Character in a String
   • Better Compression of String
2. 2

   Technical Coding Round 160 min

   This round was led by a sharp SDE-2 interviewer. The first question was on flowers and bouquets, I began with a simple idea, then used binary search to make it faster. The 2nd problem was a dynamic programming challenge counting subsequences. It was harder For the leadership stuff, I was asked about earning trust and owning up to a mistake. I answered them, but wished I’d prepared more.

   • Minimum days to make M bouquets
   • Distinct subsequences
3. 3

   Technical Coding Round 2 (DSA)90 min

   This hour-long interview was with an SDE-2 engineer. The first question was about asteroids floating in space. I had to figure out which ones would collide and destroy each other, depending on which direction they were headed. I used a stack to keep track of them, and I made sure to check for any unusual cases, like what happens if all the asteroids are going the same way or if certain ones are extra large. Next, I had to solve a problem where I needed to find a group of numbers in a list that add up to a specific total. At first, I thought about checking every single group, but that would take too long. So I used something called the sliding window method, which lets me skip a lot of the groups I don’t need to check, and I could find the right group much faster. After each problem, I clearly described my thinking and why my approach.

   • Asteroid Collision
   • Count subarrays with given sum
4. 4

   HR Follow-Up10 min

   A few weeks later, I received a call from HR, informing me that they would continue with my interview process, but due to hiring freezes, they had to delay the next round. This was unexpected, but the HR assured me that my application was still in progress.

What came up