Oracle Interview Experience (On-Campus)

On 12th July we got to know that Oracle is visiting our campus for campus hiring. Its Online Assessment(OA) was scheduled to be on 25th July and the interview on 28th July.
OA round comprised 4 sections. And each section had sub-sections and each sub-section had an individual timer.

They are offering an Associate Software Engineer / Associate Application Developer profile

These 4 sections were:

• Aptitude and Reasoning.
• Advanced Coding Questions
• Computer Science fundamentals
• Verbal Ability

Aptitude Section: Subsections were-

1. Aptitude 10 questions 12 mins. (Moderate to tough) (Time management is key)
2. 8 Data Interpretation Questions 6 mins. (Smart move to eliminate options as a lot of calculations was required).
3. Reasoning Questions – (10-12 questions) and 10-12 mins. (Number series (moderate), pattern (good level), puzzles (lengthy, time-consuming).

This section is more like a race against time.

Advanced Coding: 2 subsections:

1. 16 DSA questions in 25 mins. ( For name sake it’s DSA, but is Trees and only trees). Only 1 array question and the rest AVL, binary trees questions.  It was all MCQ questions but very long situational statements, and options had codes provided. So, the key is to grasp the important aspect from the question and eliminate the options. It is again RACE AGAINST TIME.
2. 8 flowchart questions for 12 minutes. It had a problem statement with an approach to solve it and that approach’s flowchart is being made. Now it had some blank boxes. We had to fill them with the options that were provided. 2 problem statements and 4 questions from each problem statement.

Computer Science fundamentals: 2 sub-sections. Both had OS, OOPS, DBMS and Networking questions. Basic conceptual questions. Not directly available anywhere. If basic concepts are clear then easy otherwise moderate level.

Verbal Ability: It also had 4 sub-sections-

1. Grammar (8-10 questions).
2. Sentence Rearrangement
3. Comprehension
4. synonyms antonyms and direct indirect and voices.

The results were declared the very next day (26th July). After this round out of around 700 students, only 65 students were able to clear the first round and head over to the interview process which was scheduled to start at 10:30 on 28th July. We hardly had 30-35 hours to prepare for the virtual interviews.

VIRTUAL INTERVIEWS: It is comprised of 3 rounds. Different timing slots were provided beforehand for the first round. And based on performance, we were either told to leave the meeting or to stay back for further rounds. So all the rounds were elimination rounds.

1. Technical
2. Technical
3. Technical + Managerial + HR. (In some cases it was purely technical, no managerial questions were asked, but in my case they did).

First round: My time slot was noon. It started around 12:40 and it lasted for about 45-50 mins. She was a very humble and sweet interviewer. And since she could see that I was nervous, so she started the conversation on a very friendly note. And then, she introduced herself first followed by my introduction, And she told me to explain any one of my projects. I explained the under-progress NLP(ML) project in which I have not used the database as of now. Then, when she showed interest in knowing the database, I explained how I was going to use the DB in that project. Along with that I also explained to her my internship project where I have used the DB and how I have implemented that.

Then she moved to OOPS concepts. What is it? And why do we use it? What is a reference object? Then, name all the pillars, then she asked me about inheritance. How it is achieved? After that, she asked for multi-level inheritance. And then, she asked me if multi-level inheritance possible in JAVA. Since I code in C++ so wasn’t aware of it in java. I replied since I code in C++ and there it is possible. And since it is a concept of OOPS, and the concept remains the same, only implementation is different, hence it might be possible. Then, she corrected me and told me the concept. She also touched on some basic OS concepts in short. Moreover, she was constantly going through my resume and checking each and everything I mentioned. She asked me about the hackathon I participated in. I was explaining it but since I have uploaded the presentation link and certification link which she opened. So, told me to stop and move to the coding section. She gave me the hacckerank link. And 2 coding questions:

1. https://www.geeksforgeeks.org/problems/finding-middle-element-in-a-linked-list/1
2. https://www.geeksforgeeks.org/problems/count-leaves-in-binary-tree/1

After that, I took feedback from her on my performance. She appreciated my technical skills and told me that my introduction was prepared and was not spontaneous. She was correct as I had mugged up the introduction and I would not recommend this to anyone. 😛

Second round: Then, around 1:30 I was done with my first round. And in the break-out room, there was someone from the team, she was giving break-time for lunch to a few students only. Then, I asked her if I could also get a break. She allowed me. So my break time was from 2:00-2:30. After this round, I was hoping to qualify for the next round. And then after waiting for 2 hours. My second round started at around 4:30. He told me to introduce myself and quickly jumped on to ask questions. He even did not turn his camera on. It is a disadvantage as an interviewee because, in the first round, I could see the reaction of my interviewer whether she was satisfied with my answer or not. And based on her reaction either I elaborated my answer with examples or I stopped. But in this case, I had to go with my instinct. He started with the OOPS concept. He told me to share my screen and code all the concepts in notepad.

I started explaining the concepts and took examples and I coded them. He was constantly giving me a lot of instructions. He made me code all inheritance, polymorphism, and abstraction concepts. Simultaneously asked me the difference between all of them while I was coding. He told me to make different methods, members, etc. Asked me about early binding, and late binding concepts not directly but via code/situations. He gave me situations when I was doing method overriding that how can I call both overridden and parent methods with the same object. He even went to virtual functions and object pointers. In-depth knowledge of OOPS was required to answer all his questions. As they were not direct and some were purely situational about whether it is possible or not.

Moreover, after polymorphism when we shifted to abstraction and pure virtual functions. He asked me about the use case of abstract class and pure virtual functions. Why do we at all need the abstract class if its object cannot be created? After explaining this, he went on to the difference between abstraction(I explained at last) and encapsulation(I explained at the beginning). He wanted an in-depth answer. He cross-questioned a lot. And what I felt was, that he was trying to test me if I can work under pressure or not and whether my foundation was strong or not. 

This round was not over yet. After the whole OOPS discussion, he asked me to clean my notepad and make 2-3 tables which he gave. And then asked me SQL queries. Before that, he asked me some general DBMS questions. Then asked me to write queries.

• Fetch data from both tables. I joined using the primary key, foreign key, etc.
• Asked me if the primary key column or foreign key column had NULL values, can you fetch the data from the same query? I explained the primary key constraints followed by the referential integrity concept and explained the Outer join that would resolve this problem.
• Further asked me for nested queries and, aggregate function queries. Find max salary, second max salary, Nth max salary.
• Order by queries etc.

This round was challenging but I was satisfied with my performance. I was able to answer almost all his questions. And was confident that I would progress to the next round. The result was instant. As soon as I reached the breakout room. the member from Oracle told me “If you would be shortlisted for the third round, you would be directed to the next room automatically else we would ask you to leave.” By then, 20 students were already done with their last round. In a few moments, I was transferred to the round 3 break-out room where 8-10 others were already waiting. There we all were waiting for our turn for the last round. I waited again for about 2 hours, it was around 7:20 that I was called for my last round.

Third round: She quickly asked me to introduce myself stressing about what kind of projects I have done in my internship and my final year project. I explained my final year project, the same one I did in the first round. but this time, it was a different experience. She started cross-questioning, I was not able able to understand her question and then I explained what I did, she further asked me questions. So finally, I shared my screen and showed the code, and explained her with that. She was kind of interested in my project. And seeing my code and stuff and my idea. She was impressed. She said it is a wonderful project and very unique. Since the project idea to everything was my own, I could explain to her where the idea came from, what difficulties I faced what technology I used, and why I preferred it over others. So, this discussion was about 20 minutes long. After that, she asked me about OS concepts on memory management, paging, etc. And 2 OOPS questions-

1. Inline Functions in C++.
2. Friend Function in C++. I gave operator overloading examples in the friend function.

So, because of that, she gave me a hacckerank link there she made a class in C++ and told me to code operator overloading. To print the first and last name together (concatenating 2 strings). After that, she gave me a coding question to solve.

1. https://www.geeksforgeeks.org/problems/non-repeating-element3958/1

Cross questioned me on unordered map use, time complexity, etc.

Then she started asking me HR questions.

• Where do you see yourself in the future, What work you would want to be doing?
• Since oracle works on java, I explained I would learn it and do it. To that, she had a follow-up-
• You can learn it in a few weeks, but you can’t master java as it is vast. Suppose you are currently working on java then 6 months later, there is a requirement to work on a C++ project, so would you shift since you would be in the learning phase of java? Would to choose to work on the new project or stick with the current project?
• I explained my choice and she further asked me what do I expect from Oracle. If you have been working here for 4-5 years, what kind of projects would you want to do? As an automation engineer (used a bit in my project) or as an SDE or some other interest?
  With all of that, the last round was over on a very good note. I was satisfied with my performance and I was completely exhausted. I went to sleep, and to my surprise, the result was declared that night only. I woke up from the calls of my friends, congratulating me on getting selected with 19 others.