Hi everyone, I had interviewed at Amazon a couple of months back for data engineer role and I am sharing my experience here. Before that I would like to reiterate the age old advice that corporate is not your friend. After 2 rounds of interviews which went fabulous and the interviewer telling me that it's one of the most fun interviews he has taken, I was ghosted by the organization. I neither received a rejection nor a selection mail. I contacted the recruiter who had set up my call and she said she is out of the loop and will get back to me (spoiler alert: she never does). Anyway here's how it went for those who are interested.
Round 0: Technical Assesment
This was a 60 min long online assesment round where the questions asked were of simple data structure and CS Fundamentals. Prepare database concepts and operating systems pretty well.
Round 1: First Interview: Data Structures + SQL
This round was the easier of the two rounds where the interview began after an informal introduction. The first thing they threw at me was an easy leetcode question(something like balanced paranthesis) after that they asked a medium leetcode problem regarding graphs(was very standard). Since I was coding in python they asked me a few questions about the language, I don't remember them but I think they would depend on the language you are coding in.
After this I was asked to write a SQL query which was similar to this problem followed a by question on difference between RANK() an DENSE_RANK(). After this they asked me about my projects and if I have deployed them, since they were all deployed I walked them through the deployement process. The interview ended here after 40 minutes of discussion.
Round 2: Data Warehousing Concepts + DBMS + SQL
This was the harder of the two rounds and in my opinion more fun of the two. The interview began with two-three SQL questions, they were not standard but were similar to those present here. After this we discussed data warehousing concepts about OLTP, OLAP databases and how they are different, standard questions about snowflake vs start schema were asked. Following this we started a discussion on MapReduce since I had worked with it in my previous internship which led to me describing my previous internship project as well. For the final discussion we imagined an online delivery system and discussed it's analytics. We discussed mostly how the tables would look like, how the ETL pipeline can be setup, and some other questions on size of data and it's storage. These were mostly adhoc questions where the focus was on discussion rather than finding the right answer. After this I was again asked to write a few queries on these newly made database tables. Finally the interview came to an end after a long 50 minutes.
This was supposed to be the last round but as I stated above I never received anything further.
Preparations Tips:
- Prepare SQL very well, try out all kind of queries especially those involving window functions. I believe this is the most focused part in the interviews so don't skip out on this
- Learn about Data Warehousing concepts, a short introduction which includes intro to ETL pipelines, OLAP vs OLTP etc should be fine.
- Practice Database schema design and DBMS concepts as much as you can.
- Data Structure questions are easier than SDE roles but they are still asked so prepare them all.
All the best!
