Oracle | MTS (Server Technology) | Bangalore/Hyderabad | August 2022 | Offer ✅✅

My interview journey for the MTS (Server Technology) role at Oracle in August 2022 began with an Online Assessment. It was 90 minutes long, which was more than sufficient. The OA had four sections: one easy-medium coding problem, one REST API problem (GET requests, data fetching, calculations), one SQL problem (joins, group by, aggregate functions), and 6-8 MCQs on data structures and aptitude.

Next, I had Technical Interview 1, which was 45 minutes and DSA-oriented. The interviewer started by making me comfortable, asking about my day. After introductions, I was given a Hackerrank link. My first coding problem was to determine if any permutation of a given string could be a palindrome. I discussed a brute-force approach, then moved to an efficient hashmap-based solution, which I solved and dry-ran. This led to questions about hashmaps: why unordered_map, differences between map and unordered_map, internal implementation, chaining, and linear probing. The second problem was to delete a node from a singly linked list given a pointer to it, and whether the last node could be deleted. My third problem was to find the starting node of a cycle in a singly linked list. I solved all three problems and tested them on the editor.

Technical Interview 2, lasting 1 hour 10 minutes, was a mix of project discussion, DSA, and behavioral questions. It felt somewhat unstructured. The interviewer asked about my previous interview and my performance. I then introduced myself and talked about my interesting academic and corporate experiences, particularly my work at my previous organization, managing challenges with new technology (Mendix), and projects where I was part of the first team using it. I was asked to compare academic vs. corporate life, my motivation for pursuing a master's, and my favorite subjects. Given my project's use of sockets, I was asked about socket programming and alternatives for real-time communication. He then probed into my use of DBMS, algorithms, and OOPs in my projects. We discussed my choice of Firebase (NoSQL), comparing it with relational databases. Questions on Firebase authentication, JWT tokens, and alternative authentication mechanisms like session authentication followed. I also discussed a debt-simplification algorithm I implemented, which used a heap. I explained min-heap and max-heap, including push, pop, and heapify operations, and started implementing max-heap quickly before being interrupted. Finally, I was given a linked list problem: insert a node into a sorted singly linked list at its correct position.

My final round was Technical Interview 3, lasting 50 minutes, focusing on database design and OOPs concepts. I had expected an HR round, but this was a mix of behavioral and technical questions from a very senior Director of Engineering. He initially checked my attentiveness by asking about previous interviewers and questions. I could only recall the first interviewer's name. We then delved into 'Why Oracle?', comparing it with my previous work experience and contrasting it with other companies. A Hackerrank link was shared for a complex SQL problem: retrieving 1st, 2nd, and 3rd place finishers per category from a university competition, along with student details. I discussed table relationships, foreign/primary keys, and 3NF, then drafted a SELECT statement. I initially missed the LIMIT keyword due to exhaustion. Lastly, he asked about use case, class, sequence, and component diagrams, and their importance, which I explained with examples from my M.Tech studies. I asked him about his journey at Oracle and his various roles.

I was informed no further interviews were scheduled and left the meeting, assuming rejection as there was no HR round. However, after four hours, the results were out, and I was among the five M.Tech candidates selected, receiving an offer.