Amazon Software Development Engineer interview questions

Recruiter emails you with details on what to read up on and be prepared for for the interview. I had 2 in person interviews (45 minutes back to back). Each was a different technical question. Straight forward, a couple behavioural, past project questions from both interviewers. The interviewers try their best to leave the candidate with a good feeling (company policy), so it's hard to get an idea of where you stand or how you're doing at times.

I got contacted via Linked In by a recruiter. The recruiter was always very nice and very helpful; the recruiting people gave me advises and told me what to expect in the interviews and what topics to study, it felt like they were kind of on my side and wanted to help me succeed in the interviews. I first got a phone technical interview that lasted about 30 minutes. They asked me some general data structures questions and then we used ColabEdit for coding; I just got one single coding problem to solve, they asked me to write function to efficiently look for all the phone numbers from a list A that were part of a list B (I solved it by using a Hash Table and my interviewer was happy with the solution). Then I got a second phone interview. The second interview was very similar to the first one; I got some data structures and algorithms questions and then they gave me another coding problem to solve on ColabEdit, they asked me to write a function that would receive the root of a binary tree as input parameter and would restructure the tree so that the final result was the same tree but vertically mirrored. I wrote a function and my interviewer was happy with it. After the two phone interviews, they asked me to fly to Seattle for the final round of interviews that last the whole day. They put me in a nice hotel and payed for all the expenses. I got 5 interviews in total, each one lasting about 1 hour. First onsite interview: They asked me general questions and asked me to describe some of my past projects; then asked me to design and code a Cache system. They told me they didn't know the right answer and they just wanted to see what I would come up with, they participated in the design suggesting things and asking questions. Second onsite interview: They asked me to create an algorithm to find all the strongly connected components of a graph (very though question in my opinion). Lucky me I had studied some graphs theory and I was able to remember Tarjan's algorithm to find strongly connected components. I reproduced the algorithm from what I remembered and I think I did it right (although some times the interviewers are more interested in seeing how you approach a problem rather than knowing the solution, so not sure if knowing the answer played against me). Third onsite interview: One of the amazon guys took me out for lunch to a place neat place near amazon and we just chatted and towards the end of the interview he started asking me some behavioral questions. Fourth onsite interview: On this one I interviewed with a PM and a leader from one of the Amazon teams. The Amazon team lead asked me to design an eCommers website. I think I struggled a little bit with this one because I was not prepared for architectural questions or designed, I kind of just focused on algorithms. Fifth onsite interview: The last guy just asked me to write some easy code to perform some task that I forgot, but it was very easy. In all the 5 interviews they all asked me behavioral questions related to the Amazon Values (study the Amazon Values, this is extremely important for them). Although I struggled in the third onsite interview, I really felt like my overall performance had been great and I thought I was going to get an offer; but at the end they didn't extend an offer. I asked for some feedback to know what areas I was weak to work on them but they told me that they cannot provide feedback because of their policies.