Status : SDE2 at Indian Startup
Date : Oct-Nov 2021
Total Experience : 3+

Asked for someone to refer, got the call from the recruiter after 5 Days and recevied the OA Link that needs to be solved within 1 week.

Online Assesment : 2.5 Hrs Round (90 Mins in HackerRank 2 Questions only and some SDE Behavioural Questions and System Design Questions which were Multiple choice and asked in amazon platform).

1. Amazon Logistics Question [Could be found easily in Leetcode's Interview Questions Section] - Has done this question before, solved easily.
2. Stack Based Question [Didn't exactly remember] - Finally solved before assessment end after getting TLE lot of time.

Received call within 5 Mintues of submitting the OA from Recruiter and arranged Phone Screening (45 Mins), LLD (60 Mins) and Problem Solving Round [DSA] (60 Mins).

Phone Screening : Asked Questions based on LPs. One question based on Prefix Sum [Range Query to get the sum between L index to Right Index]. Told the logic immediately, didn't asked to implement and asked extension of question based on 2D Matrix. Tried to find out the logic and gave logic , at one place there was faullt in logic, Interviewer helped to correct it.

Call Recruiter to Know Status and It went good and inclined in Phone Screening.

LLD Round: Taken by L6 of Amazon. Problem Statment to create service which is serving/using by multiple client to serve their customer to fetch the Text from Image. Asked Interviewer How I should start answer as a Distributed System Design or Object System Design. Interviewer told to first go for Distributed one and then Object Design.
Went good as I think, Created HLD and Discussed Metrics, Single Point of Failure, 10 X Load, Failure Case, Database Design.
Interviewer asked to jot down some classes [Controller and Modal]. Created the Classes according to Object Oriented Design [Told some Design Principle which could be used in Controller and Modal - Template, Singlton and Builder and Factory].

Given solid answer of LP's Question.

Got call from Recuiter that received Posistive response in LLD, Hence wanted to schedule the HLD Round and asked for slot (Got to know needs atleast one Inclied from LLD or DSA to schedule HLD).

DSA Round: Round Taken by SDE 2. Round didn't went well and Interviewer also seemed rude to me. (I joined 5 mins earlier and blurred mine backgroud so that hanging clothes shoudn't show in chime video, Interviewer joined 5 mins late from scheduled time and first thing he asked after starting video to remove blur in rude behaviour).
Asked LPs Question based on Customer Obsession - Something you have done apart from Normal Project [without getting requirements from PM] to increase Customer Delight [Somewhere related to that]. Informed one of the points I observed in our live project and how I informed mine team on that changes are in beta to increase customer delight. Also informed him that he could see that problem in our web app. But Got response from Interviewer - Don't tell something which is not in production.
Told one more scenario based on real event in current project which prevented us to stop the XSS and how I resolved that risk which could lead in xss attack. Got responsee from recruiter it doesn't count in customer delight. I felt little broke down in interview flow.
DSA Question asked -

1. Range Query update in a very vague way. Informed you have given two method update and display . Display is used to display array and you need to implement update such that update operation will be in constant time for N Query.

Informed the Naive approach as question seems very opaque to me. Later got to informed by Interviewer that I could also modify display method. Tried to give solution where update was working in O(1) but display was working in O(Query * N). He didn't know either this is right way and told he is also doing this and maybe display should work in O(N). Asked to write code for approach which I given.

After Interview got to know about the concept of Differene Array. I didn't aware about this earlier.

2. Minimum Difference between Node and it's Ancestor.

Told Interviewer the reursion approacch based on post order traversal and done the dry run on the tree, He told that's wrong approach and will not work for other input. I got confused and mode went off. We changed the input and not sure in-first go approach didn't returned right answer in dry run [Not sure how, Interviewer raised his voice again look he beecame happy]. I done the dry run and found the mistake i've done in dry run and got correct answer. Created another set of input and ran the dry run approach worked since that was right approach. At last he asked to code the approach. I done the code and was handling the edge case while going in recursion and at that time interview informed wee have crossed interview time and any question i wanted to ask.
I asked for the hint on question 1 and how to solve, He informed we don't discuss solution in the interview.

Got call from Recruiter that Round doesn't went good and vote was not-inclined and they'll arrange Bar-raiser if they'll get Inclined vote in HLD Round.

HLD Round : Round taken by 2 Managers [One might be shaddow] of Amazon. Asked the question on LP's based on Deliver Result and HM was impressed with resume on work which I did in 3 year of span.

Design system for the Stock Exchange where watchlist functionality needs to be implement. I designed the distributed event based system and told the trade-off between the solutions and what will i use if i get X number of stocks listed in future. Discussed lot of system metrics on non functional requirements. Design Choice of Database, where to place cache, communication protocol, scenario for scalabllity and what would if we get 100 X load during Country Budget Season.

Round went really well and HM told about what his team does.

Got feedback from Recruiter that they'll arrange the Bar Raiser as a Next Round.

Bar Raiser: Grilled 35-40 Mins on LPs Question and One Question based on the Next Frequeny of right side greatest element. Discussed the approach using Stack , took some time as i was also doing dry run with multiple approach. Interviewer was okay with approach and asked to code, Done the code and done dry run (some - cases were failing), started to fix those in code. Stopped by Interviewer that he got the point and solution and we have crossed the time.

Got call from Recruiter that they'll do debrief next day and will let you know. Asked how Bar Raiser Round went.

I was expecting result in positive as one only one round went horrible and all others went really good. But next day In evening got text message from Recruiter - Ur profile is not shortlisted for sde2 role with us.

Not sure out of total 6 rounds (Including OA), One round could make that much difference.

Sharing so that, It could help community in getting refernce. I'm fed up with trying my luck with Amazon. Last I tried in 2019 and got negative feedback. I'll try luck with amazon in future again may be after 2 years and let's see what will happen.