Oracle GBU Interview Experience | On-Campus 2021

Oracle came to our campus in August 2021 for the GBU vertical hiring. The selection process was divided into five rounds:

Round-1 (Aptitude and Computer Fundamentals) (2hrs): This is an online test conducted on the eLitmus platform where video and audio proctoring is performed and screenshots will be taken periodically. This round was divided into several sections:

• Quantitative Aptitude
• Logical Reasoning
• Contextual Communication(English)
• General Computer Programming MCQ (C, C++, Java, Python, DSA)
• Technical Computer Science in Oracle (OS, DBMS)

 Some aptitude questions, Comprehension passages, and several flow charts, pseudo-codes were given and asked to predict the output in this round. There was no option to revisit the questions once marked and there was a negative marking of -0.25.

Round-2 (Coding Round) (1hr):  In this round, two questions were given, the first one is a DP problem and the second one is on graphs, both were medium-level questions and modified versions of the standard coding problems.

The next three rounds were Interviews:

First Technical Interview (1 hr): The interviewer asked me to introduce myself and then she moved on to the projects mentioned in my resume. 

• She asked me to give a brief description of my projects and asked me the relevance of my projects in today’s world.
• She compared my projects with the existing applications and asked me in what way my projects are different from them. Then she asked me to share the screen and run my latest Machine Learning project.
• Then she moved on to some coding questions. She asked me to code the Removal of Duplicates in an unsorted Singly LinkedList problem.https://www.geeksforgeeks.org/remove-duplicates-from-an-unsorted-linked-list/amp/
• Initially, I came up with the solution using HashMap, then she asked to come up with an in-place solution.
• Then, she asked me to code and execute pascal’s triangle problem. I coded it, shared the screen, and executed it in an online compiler as mentioned.

Then she asked me some basic questions in java:

1. What is a Virtual function in Java?
2. Explain the keywords transient, volatile, and their relevance with Serialization in Java?
3. How to directly initialize a HashMap (in a literal way)?
4. What is the -Xms and -Xmx parameters when starting JVM?

Then she asked me few basic SQL queries on joins, nested queries, and the differences between SQL and MongoDB. Then she asked me the real-world applications of Stacks, Queues, and all OOPS concepts. Then she asked me two puzzles(both of them were slightly modified and asked from the existing standard puzzles). Finally, she asked me if I had any questions.

Second Technical Interview (1hr): The interviewer again asked me to tell about myself, then he quickly moved on to puzzles. He asked me 3 puzzles which were again slightly modified from the standard puzzles. Then he asked me to code and execute one of those puzzles with the user-defined input. I executed it in an online compiler by sharing my screen.

Then he asked me to code and execute two coding questions:

1. Given two numbers, find the LCM of those numbers. (Initially, I came up with the recursive solution using GCD but he asked me to come up with an efficient solution that doesn’t use GCD. I coded and executed it).
2. Given a large String, print the longest substring that is repeated more than twice. (Initially, I came up with the solution using HashMap but he asked me to code an in-place solution. Then I came up with the in-place solution and executed it).

Then he asked me to explain my latest project in detail and asked me the challenges I faced in that project and how I resolved them and he asked about the scope of my project in today’s world and asked me to talk about the scalability and the extensibility of my project in future. Then he asked me how would I design an efficient system that predicts the symptoms of several diseases and suggests the relevant drugs. He asked me what machine learning algorithm would be efficient for such a system and also what would be the format for the training set. I gave him my solution and then, he discussed the efficiency of those solutions and asked me to come up with better solutions. 

Then he asked me few basic questions in DBMS and OS:

1. What is a lock? Explain the major difference between a shared lock and an exclusive lock during a transaction in a database?
2. What is meant by Data Warehousing and what is the relevance of Data Warehousing?
3. Are NULL values in a database the same as that of blank space or zero?
4. What is the RAID structure in OS? What are the different levels of RAID configuration?
5. What is the major difference between Paging and Segmentation?
6. What are file descriptors, explain in simple terms?
7. What kind of resources are generally shared between threads?

Finally, he asked me if I had any questions for him.

HR Interview (40 minutes): The interviewer introduced himself and asked me how my life is going on. 

• Then, he quickly jumped into my resume and asked about the various courses I mentioned in the resume and asked me why I took those courses.
• Then he asked me the reasons that motivated me to work on the projects that were mentioned in the resume. Then he asked me how effectively I utilized the lockdown.
• Then, he asked me to rate myself out of 10 in C language.
• Then, he asked me some basic questions about keywords, conditional operators, and recursion in C, then he shared the screen and asked me to predict the outputs of few C codes related to operators and pointers.
• Then, he asked me about the extracurricular activities that I mentioned in my resume and asked me how active I am in those activities.
• Then he asked me to throw some light on my hobbies. I mentioned reading novels and comics as one of my hobbies in my resume. He asked me What I like more, Novels or Comics and Why?. I told him that an image illustrates more than written paragraphs and a picture is worth a thousand words, so I like Comics more. He said Written paragraphs make us visualize and enhance our creative imagination, then how could you say pictures are better than written paragraphs?.
• Then he asked me what Comics would I generally read. I said I usually read AmarChitraKatha comics and explained about few of my favorite stories in them.
• Then he asked me why do I want to join oracle and what makes me suitable for this job.
• Then, he talked about the different technologies they work on in oracle and on what basis they assign their employees into different segments and he discussed the Idea Picking sessions in oracle and how they give importance to the ideas of their employees.
• Finally, he asked me if I have any questions for him.

Verdict: Got selected for Oracle GBU.

Takeaways:

• Make yourself comfortable with the interviewer and ask him/her for clues if you get stuck in middle, They are there to help us.
• They won’t expect us to be 100% correct and to give an extremely efficient answer in the technical rounds. Primarily, they focus on our approach and the way we build the solution for a problem.
• Confidence is the key.
• Prepare Java, DBMS, and Puzzles thoroughly.
• Interviews started for me at 10 AM in the morning and ended at 7.30 at night and in between they made me wait in the breakout rooms with my video turned on. So be patient till your turn comes and try to maintain enthusiasm till the entire process is completed.