Status: SWE at a top firm in FinTech space, 2 YOE
Position: SDE2 at Amazon
Location: Bangalore
Date: May 2022
Background - I wasn't looking to make a switch. Talent Recruiters from Amazon have been reaching out quite aggresively over the past year. I had been solving LC on and off (2-3 questions a week for past 5-6 weeks) just to get some background in order to take interviews at my current firm. Somehow, last month I decided to interview.
Round 0 - Online Assessment
Received a link for the test. Standard 1.5hr assessment including two medium level questions followed by LPs. Questions were based on Arrays and DP. Solved one of those optimally while the other one using memoization. All but two tests failed for the latter one.
After a week got a mail asking for suitable slots for scheduling virtual on-sites over the next week. I wasn't at all prepared. I asked for a preparation time of two weeks and the coordinator agreed.
Prepration -
I've always been lazy when it comes to practicing DSA, mostly due to the reason that I don't like the idea of solving puzzles. I like to leverage the concepts when working on real world problems. I started solving LC medium to hard level questions spanning topics such as Arrays, Strings, Stack & Queues, Trees, Dynamic Programming, Graphs, Linked Lists. Used Amazon tagged questions ordered by decreasing frequency. This helped a LOT. For advanced topics such as Trees & Graphs, I studied popular algorithms, trying to cover as much as I can. Hardly covered Greedy (other than the basic ones). Total ~100 questions, mostly medium to hard, 3-4 hrs daily for two weeks.
I can rate myself intermediate to good when it comes to LLD and HLD, given my exhaustive work experience, working across 5-6 different projects, designing systems & features from scratch. I still read some HLD & LLD case studies to get a sense of how to present during interviews. Watched Uncle Bob's sessions on YouTube. Along side, I also started reading Designing Data Intensive Applications, (found it really intresting).
As the dates for the interviews came nearer, I started spending a hour daily to recall my past expierences and wrote them down, categorizing each one of them with relevant LPs and LP questions. I had to collect this data in STAR format to make it presentable.
ON-SITES (4 rounds)
Round 1 - Problem Solving & DSA
Two questions were asked. One was easy to medium level question around pattern searching. Explained my approach, coded cleanly with proper syntax in total 15 mins.
Next question was medium to hard level involving graph traversal in a matrix. Initially, I could not fully understand the problem, eventually when I understood, I implemented an incorrect solution. Got some hints from the interviewers and was able to come up with a solution but could not implement as time ran out. Interviewer asked one LP question and then took questions from me. The interview ended here.
Round 2 - LLD & Problem Solving
Interviewer gave a problem which involved both LLD & Problem Solving. Usage of HashMaps, PriorityQueues etc. along with clean code, OOP. Overall I'd rate it as a medium level. The problem was followed by LP question and the interviewer seemed quite amazed by my answers. Overall, this round went very well as per the feedback received from HR.
Round 3 - Hiring Manager
A LOT of LP questions, and I was very well prepared for these. I had a lot of genuine stories from my past experience covering several leadership principles. HM is most interested in Ownership, Deliverism & Curiosity to Learn. Several follow up questions after each LP question. Kind of an explolatory conversation which helped HM understand the kind of exposure I've received over the past couple of years. This was followed by a simple HLD problem. I started off with the framework I had rehearsed but got a bit nervous.
Overall this went okayish. I was bit skeptical after this round as this is supposed to hold maximum weightage. Did not get any feedback from HR as they were not reachable on that day.
Round 4 - Bar Raiser
Hands down - ALL LP, for more than an hour. Received really good feedback for this round.
The most important part for LP questions is, your answers should not be repeated. It looks redundant as the interviewer would have read your past feedback. This was a tip I received from the HR.
Result
Received the offer. - https://leetcode.com/discuss/compensation/2136008/Amazon-or-SDE2-or-Bangalore
Tips -
I felt that LPs and past experience along with relevant skill set matters a lot when it comes to Amazon. Yes, they do expect top notch problem solving skills, but a mistake there, can be covered by your excellent work-ex.
You need to learn to market yourself, and prove your worth. Even I'm not perfect at it. I did a lot of mistakes when tackling LPs, realized those on the fly, but gradually improved a lot in subsequent rounds. Writing stuff down helps a lot.
The amount of time required to reach a certain level of expertise with problem solving varies from person to person. Know yourself, and practice accordingly.
Pro Tip - Note that, once started with on-sites, we have to complete all interviews within 5 working days. You can choose to schedule single, multiple and even all interviews on the same day given that the slots are available. Always go with the strategy that will suit you the best based on - cooling period required after each interview, anxiety levels during wait periods etc.