Oracle Interview Experience (OCI) | IC3 | 4+ Years Experienced
Last Updated :
23 Jul, 2025
Oracle Screening Round
1. Project Discussion.
2. Inner join vs Outer join.
3. What is Indexing, how it works and its disadvantages?
4. How you authenticate third party user in your system? Authentication vs Authorization.
5. Use of Kafka in your system?
6. Git branching strategy in your organization. How a user story is completed in your organization, from development to deployment.
7. How to implement thread in java. What is functional Interface. As of java 8 since interfaces can have default methods, when we have to use abstract class and when to use interface.
8. What are Java Collections. What collection objects you have used?
9. HashMap vs HashTable.
10. Arrays vs ArrayList.
11. Hierarchy of exception class? Error vs Exception. Checked vs Unchecked Exceptions.
12. How Compiler forces to handle checked exception?
13. How to get any item in a java collection ArrayList. What is fault safe iterator?
14. Write your own custom exception, Called it from any other method.
15. What is finally block does? Will Finally block runs when there is return statement in catch block?
16. What design patterns you used?. How to implement factory design pattern? What OOPS property does factory design pattern shows?
17. What is Polymorphism and its types? Method overloading and method overriding. Does method overloading depends on type of return type of method?
18. What you look in code reviews?
19. What is Static Keyword. What happens when you add static in member variables and methods. What are constraints does static class have over when non static methods.
20. What is fail safe iterator?
Round 1 :
1. https://www.geeksforgeeks.org/dsa/sorted-array-to-balanced-bst/
2. https://www.geeksforgeeks.org/dsa/print-a-given-matrix-in-spiral-form/
3. What you look in code reviews?
4. Which java version you used and why?
5. Polymorphism and encapsulation.
6. What are REST Verbs ? What is idempotence in REST?
7. What is JDK, JRE and JVM.
8. What is Hoisting in Javascript.
9. What is recursion why it is used? Give code example.
11. Any complex REST API you made. Why it was POST API, or not GET ?
Round 2 :
1. https://www.geeksforgeeks.org/dsa/check-for-balanced-parentheses-in-an-expression/
2. How kafka works? Why not use rabbitMQ? Why not use Amazon EventBridge and Simple Notification Service(SNS).
3. What is helm in kubernetes? Do you use docker in you CI/CD pipeline?
4. Did you made any mistake?
5. How deployments works in your application?
6. Project Discussion.
7. Any Complex problem you solved?
8. Does your system auto-scales? What is the threshold?
9. When to we go with synchronous approach and when we go with asynchronous approach?
10. Did any situation happened when you completed your development, but product requirement changed at last moment? How did you tackle that condition?
Round 3 (HM) :
1. Any complex Problem you have solved?
2. Any mistake you have done?
3. Given two non-homogenous ropes, how you will measure 45 minutes of time, given that
both ropes completely burns in 1 hr and each half burns at different rates.
4. Given a string which has characters as ‘C’, ‘R, ‘L’, ‘U’. Initial there are 0 chairs in room.
i) C/L means - > a man will come, if there is empty chair, will seat there , otherwise purchase a char and sit on it.
ii) R/U means - > man will free his chair.
Find minimum number of chairs required.
Input - “CCRLLRUL”
Output – 3
5. https://algo.monster/liteproblems/1413
Round 4 :
1. HLD of out current application.
2. Why looking for job change?
3. Given Employee has (id,name), Expose REST API contracts used by third part team to perform CRUD operations.
4. How prod bugs are handled in your team?
5. How deployment process happens in your team? On which cluster your application is deployed?