Status: 4 years of back-end and game development experience
Position: SDE 2 at Amazon
Location: Hyderabad, Telangana, INDIA
Interview Panel from: Seattle, WA, USA
Date: October 10th, 2019

The process started with a message from Amazon recruiter on LinkedIn. Post that I had a telephonic discussion with him, he briefed me about the role and the interview process. Then, he forwarded me a link for online assesment. After passing the online assessment, I was required to complete a non-technical phone interview.

Online Assesment: 1.5hr

• Sort telephone boxes: Similar to Reorder Data in Log files
• Optimization utilization in Aeroplane delievery: Similar to Optimization Utilization

Onsite Interview: [4 Rounds, 1hour each]
After completing the above steps I got an invitation to join Amazon for an onsite interview during the Hiring Event. Below rounds were non-knockout rounds..

Round 1: [Object Oriented Design | By Senior Developer]

• Leadership Principles(LP): Tell me about a situation when you had a conflict with your manager.
• Design OOPs for Amazon Alexa devices. Echo Show, Echo Dot and, Amazon Echo. These devices have different input(typing, voice), output(sound, display) and power(battery, plug-in) mode. Your Design should be able to handle different input & must respond with the correct output when Alexa is asked about its battery status(i.e X% charged or plugged-in).

Round 2: [Coding | Bar Raiser]

• LP: Tell me about a time when you innovated and exceeded the expectation.
• Almost similar to leetcode - stream of characters, but it was rephrased in terms of DNA sequence and Genome List. - Trie DS

Round 3: [System + OOPs + Database Design | By Senior manager]

• LP: related to Customer obsession LP
• Design an Online Table reservation system for a restaurant. No specifications were given, I have to demonstrate the process of requirement gathering first and then proceed with the system, oops and DB schema design.

Round 4: [Coding | By Senior Developer]

• LP: about LP - Have Backbone; Disagree and Commit
• Leetcode Word Ladder II, since I answered it relatively quicky so I was asked a lot of follow-up questions. - Graph DS

Telephonic Hiring Manager: [1hr | Semi-technical] It's about the work I am doing in my current project and situations/problems which I faced during production, development and deployment phase.

I enjoyed interacting with Amazon recruitment and Interview panel. These guys are highly professional, humble, positive and friendly in nature.

Thoughts and resources on preparation:
Behavioral and LP: There are 14 Leadership principles, which are must for onsite interview. STAR method; share details of your previous and current experiences; don’t stay on high level

• Write down 2-3 examples using the STAR method and practice them out loud
• A list of sample questions can be found here; https://www.thebalancecareers.com/behavioral-job-interview-questions-2059620

Online test: Here is a nice collection of questions to prepare for online assessment. Mostly these are from easy/medium category questions related to Arrays, sorting, optimization. Look-out for the wordings of the question, sometimes a straightforward question can appear alien to you.

Onsite F2F Interview: This is the ultimate battleground, which must be conquered, survival is not an option. To avoid the human bias, Amazon doesn't allow the interviewers to share feedback between each other, this can only be done after individual submission of results by the panel.
For SDE all rounds will be concerned about coding with DS. But for SDE-2 and above it's 60% coding 40% design(System + OOPs design). Please wait few minutes and think before you jump on the solution, even if you know the answer.

• Bar raiser: Interview tips for bar raiser. Bar raiser is a senior manager and has a big say in your selection.

Hot DSA topics: Binary Tree, Trie, Graphs, Topo sort, BFS, DFS, recursion, Heaps, Matrix problems, Backtracking, DP, sliding Window, Two pointers(Please, don't curse me if you think I mentioned everything).
Keep practicing Leetcode question as much as you can. Try to stick to a specific set of problems/topics and practice all variations of it until you're master of your domain and then proceed to next set. Every question fits into one or more data structures and algo. pattern. To train your brain for identifying these patterns, please refer Grokking, Coding patterns and leetcode filters.

System Design: Grokking, System Design, Sys-Design-Primer, System Design Interview, cheat sheet, practice questions. Below are few steps, but not all interviewers are intrested in all steps, some wants you to skip to the next steps, therefore its good to ask:

• Ask smart clarification questions about use cases and constraints (deal with ambiguity). Focus on high availabilty and scalability.
• If interviewer is intrested then perform an estimation for storage and requests per second and over the years.
• Walk through your design from end to end. What components you need for this service? Can you show the dataflow and connection among these components? (Database, service, system, API…)
• Define bottleneck in your design to scale up; Optimize and scale your solution. How to load balance on the server or the DB side? How to build the distributed system?
• Do you know the trade-offs among different solutions? Can you explain the logical reasons well behind your choice of technology?
• Talk about system operational excellence. How to monitor system performance? How to catch the failure? How to fix it?

I have gone through a marathon of 6 months DSA and system design training before I started appearing for interviews of companies like Google and Amazon. It's not that difficult as it appers, It's all about time, Hard work, discipline and most importantly self believe. If you want something you never had, you have to do something you've never done. Happy Coding and Good Luck! मित्र;

[Edit]: Added few more resources, links and insights. Will try to post solution for the Amazon Echo OOPs problem in the comments.