Amazon Interview Experience for SDE 2

Round 1: DS

Implement a hit counter. Aim is to get number of hits in last 5 minutes and 10 minutes. Duplicate hits can also come at a particular time instance.

GFG Link: https://www.geeksforgeeks.org/design-a-hit-counter/

Given an unsorted array of non-negative integers and a sum value, find the subarray whose sum of elements is equal to given sum.

GFG Link: https://www.geeksforgeeks.org/find-subarray-with-given-sum/

The question was further extended such that elements can be negative also and the given sum can be negative also.

Some questions on projects I had worked on. He asked me about any task that was not satisfactory but still went into production. How did you talk to your manager and take initiative to fix it?

Round 2: Hiring Manager

Train reservation LLD – full discussion on various entities involved, there attributes and how you will serve the train search results.

Asked me about any conflict I had with any team member and how was I able to resolve it.

Asked me about something that was released into production and was modified later.

He asked me about some microservices I worked on, since I had mentioned them in my intro. He asked me to explain the design of some services that I was handling.

Round 3: Design

There was only 1 design question that was asked in this interview.

Food Delivery app design – Brief HLD was discussed but mainly I had to make and explain  the entire LLD – the entities involved, attributes, service classes for various flows like search, order, payment, track order, etc.

Round 4: Design + DS

Tinder design. Mainly he was interested in HLD and how will you implement various flows.

DS question 1: Find maximum sum in an array such that no 2 numbers are adjacent to each other.

DS question 2: Minimum length Substring in a string S that contains all chars of another string T.

Round 5: DS

Asked me about projects I worked on. Also asked me to explain some recent thing I had developed.

Given a matrix of pixels(each pixel has colour code and brightness value associated with it), find a region with maximum brightness. A region is an area of only one colour.

Given a method deploy(a, b) which deploys all commits of project A from 1 to a and all commits of project B from 1 to b. deploy(a, b) gives true if all commits i.e. 1-a and 1-b are not faulty. Otherwise false. We are given that deploy(a, b) is failing and there is only 1 faulty commit. How will you find that faulty commit.

TIPS:

1. Practice writing code on paper. You are expected to write production ready and bug free code of all DS questions.
2. For design, focus on concepts rather than the exact design solution. It will help you be ready for any kind of design problem.
3. The interviewers give high attention to behavioural questions like that asked in Hiring Manager rounds. So make sure that you prepare for them beforehand.
4. You should also be able to explain clearly all the projects that you have done in your current organisation.

Besides that – Be confident, Believe in yourself and All the best.