I got an invite for a hiring drive last year & made it to the final interview call with a US boss. I was rejected as perhaps I erred or fell short on some technical questions like BFS vs DFS or some questions related to tree traversal, at that time.
This year, again I was contacted by a recruiter for an SDE2 role in Gurgaon. I applied for it and had a telephonic round first. It was a challenging round, with a question requiring recursion/dynamic programming kind of approach, with a complexity analysis and of course, discussion on how my proposed solution could be improved or made better. I wrote some code which seemed to answer or solve the question and hence, I guess, I was short-listed for the next phase of the process, which was an in-office sprint of 5 in-person interviews in a day.
I had read about the 5 rounds of interview typically, for an SDE2 position. I read that it begins with some coding rounds, with the final few rounds being the design rounds. However, in my case the first round began with a discussion of my work and resume and shifted to the design discussion. Surprisingly, he didn't ask me any coding questions but mainly asked me to describe a complex project I had delivered, asked me questions on that and finally asked me to design a payment system for a cab booking app (like Ola, Uber,etc..). He asked me to just write the names of the classes of the backend Java code and give a high level overview of how the system would work. I told him my approach of using some front-end app to make some DB calls or execute queries to update the payment records or database but he wasn't satisfied and I haven't found a plausible answer yet.
The 2nd interviewer was perhaps the hiring manager, and he more or less asked me the same questions (apart from, why Amazon?) - describe project, questions on design of the project, design the same payment system, issues I might have had with my manager at workplace, my work preferences (individual or team work), etc.. It was a fine round and he seemed ok with my payment solution explanation/approach, if not impressed or completely satisfied.
The next round was similar but a bit different. The interviewer, perhaps another SDE2 from the same team, asked me to design a Java package that would be used by other people to read and process CSV files and load them into a database. Now, here he wasn't concerned about the low-level implementation details, like reading a file or writing to a file/database but was concerned about and wanted me to show the Java interface that would be presented to the user for such a package, how that would be implemented and how a user would use it to handle and process different kinds of files (by passing an Enum type for different kinds of files). There seemed to be some ambiguity in my understanding so we spent much time to understand or frame the problem correctly and in the end he wrote a bit of code on paper and I completed the rest. The code was simple and the solution pretty straight forward, without any complex constructs or catches so I wasn't sure what he wanted to test or if I nailed it correctly.
The 4th round was, I think, with another manager and was again about my projects, work exp., (same stuff over and over again), etc. He he finally asked me to design and implement the search box drop down list/suggestion functionality on Amazon. We discussed my approach, the design, it's complexity, how it could be improved and then he finally asked me to code it. I think I did well in this round even though the code I had written wasn't the most optimal one or close to the best I could do/have described. However, I was too exhausted at this point and it was later half of the day.
I thought that I had pretty much explained myself and what I knew as per their expectations and now could be told of a decision and didn't really need another round to judge me. However, to my surprise again, they actually conducted a fifth round and the interviewer, a thin nerdy SDE2, came over and asked me coding questions. Rather than beginning with coding, they chose to end my process with coding questions and that also seemed to be a particular class of coding problems (backtracking, matrix traversal, find the largest continuous path, max sum subsequence in an array with conditions, etc.) that I couldn't answer well and then I knew.
Afterwards, the HR escorted me to the exit without any comments on the interviews. I knew I wasn't gonna make it, at least not with flying colors but the whole process felt like a some sort of an experiment to me. The last coding round could have been the very first to filter me out, but they chose to schedule things the way they did, and also gathered the design diagrams of an internal tool that I drew so well, through their meticulous grilling.
