Fujitsu India Java Developer Interview: Rounds, Questions and Preparation

What the job involves

Java Developers in Indian IT services build and maintain enterprise applications for clients, often working on Spring Boot microservices, REST APIs, and database integrations. They collaborate with onsite teams, fix production issues, and follow Agile delivery. Freshers usually start with training and then move to billable project work.

Core Java and OOP

1. 1

   Explain the difference between ArrayList and LinkedList with an example of when you would use each.

   Mention internal data structures, time complexity for get and add, and memory overhead. Give a real use case like frequent random access versus frequent insertions.

2. 2

   What is the difference between an abstract class and an interface in Java 8?

   Cover default and static methods in interfaces, multiple inheritance of type, and when to choose one over the other.

3. 3

   How does HashMap work internally in Java?

   Explain hashing, buckets, equals and hashCode contract, collisions, and treeification in Java 8. Mention load factor and rehashing.

4. 4

   Write a Java program to reverse a string without using StringBuilder.

   Show a loop from end to start, or use char array. Explain time and space complexity. Handle null and empty string cases.

Spring, SQL, and Practical Scenarios

1. 5

   What is dependency injection in Spring and how does it help in a project?

   Define IoC, constructor versus setter injection, and how it reduces tight coupling. Give an example of a service class injected into a controller.

2. 6

   Given a table Employee(id, name, salary, dept_id), write a query to find the second highest salary.

   Use a subquery with MAX or a window function like DENSE_RANK. Explain the difference between RANK and DENSE_RANK for ties.

3. 7

   You are asked to fix a production bug where an API returns 500 for some users. How do you approach it?

   Check logs, reproduce the issue, review recent changes, and add proper exception handling. Mention communication with the team and writing a test to prevent regression.

4. 8

   How would you design a simple REST API for a student management system?

   List endpoints like GET /students, POST /students, use proper HTTP methods and status codes. Mention request and response JSON, validation, and database layer.

Project and Role-Specific Questions

1. 9

   Explain your final year project. What was your role and which Java technologies did you use?

   Keep it structured: problem, your contribution, tech stack, and outcome. Be ready to answer follow-ups on any technology you mention.

2. 10

   What is the difference between a monolithic application and a microservice? Which one would you choose for a small project?

   Compare deployment, scaling, and complexity. For a small project, monolith is often simpler. Show awareness of trade-offs.

3. 11

   How do you handle exceptions in a Spring Boot application?

   Mention @ControllerAdvice, @ExceptionHandler, custom exceptions, and returning proper error responses. Give a short code example.

4. 12

   What is the difference between checked and unchecked exceptions? Give examples.

   Define compile-time versus runtime, list IOException and SQLException as checked, NullPointerException and ArithmeticException as unchecked. Explain when to use each.

Behavioural and HR Questions

1. 13

   Why do you want to join a services company like Fujitsu India rather than a product company?

   Focus on exposure to diverse clients, structured training, and long-term career growth. Avoid saying product companies are better.

2. 14

   Tell me about a time you worked in a team and faced a conflict. How did you resolve it?

   Use STAR method: situation, task, action, result. Show listening, compromise, and focus on project success.

3. 15

   Are you willing to relocate to any city in India or work in shifts based on project needs?

   Be honest but positive. Express flexibility and willingness to learn. Mention any genuine constraints clearly.

4. 16

   Where do you see yourself in three years as a Java Developer?

   Show a path from learning to contributing independently, then mentoring juniors. Align with the company's project delivery model.