Amazon SDE 4 Round Interview - Interview Assistance

This was a virtual onsite interview. The interviewer told me at the beginning that they would be taking a lot of notes and asked me not to worry about it too much.

Behavioral Questions (BQ) part: The first question was about Ownership. They asked if I had ever faced a situation that wasn't within my responsibilities, but I still took the initiative to handle it. The second question was about Deliver Results. They asked for an example where I had to deliver results despite tight deadlines and limited resources.

Coding/Design part: This round had a bit of object-oriented design. I was asked to write an EventTicketSystem, which would support selling different types of tickets (such as concerts, movies, sports events). The system had to be designed with scalability in mind, so that adding new types of tickets in the future wouldn’t require major changes to the logic. I used a simple factory pattern to abstract the ticket types, with the core logic placed in a ticket seller class. The interviewer challenged me a bit: "What if the pricing rules for each type of ticket are different?" I explained that I could use the strategy pattern to decouple this, and I felt this was a point that scored some extra points. The code was a bit lengthy, and I finished it just in time. The interviewer said, "That’s pretty aligned with what I expected," and even smiled.

The system design part was to design an Amazon product recommendation system, which I personally felt was somewhat challenging. The overall atmosphere was pretty good, and the client feedback was great. But it seems like Amazon’s bar is getting higher recently, and behavioral questions often touch on the bar raiser.