VISA IS HIRING : SW ENGINEER (JAVA BACKEND

VISA IS HIRING : SW ENGINEER

• Qualification :Bachelors degree or with an advanced degree
  
• 2023/2024 passed outs with 6 months to 1.6 years of experience
• Experience with Java, springboot
• Experience with Spring, hibernate and RDBMS technologies like PostgreSQL, Oracle
• Proficiency developing unit and automation scripts using Karate, JUnit etc.
• Knowledge of streaming pipeline
• Location: Bangalore, India

Apply through the link:CLICK HERE (Apply before the link expires)

Interview Questions and Answers for sw engineer : JAVA Backend Visa

1. What is Spring Boot and why do we use it?

Answer:
Spring Boot is a Java framework that helps you build web applications quickly without writing a lot of configuration code. It comes with many built-in features like auto-configuration and embedded servers (Tomcat), so you can focus on writing business logic.

2. What is the difference between == and .equals() in Java?

Answer:

• == checks if two objects point to the same memory location.

• .equals() checks if the content inside the objects is the same.
  For example, two different String objects can have the same value but still not be equal using ==.

3. What is Kafka and how is it used in backend systems?

Answer:
Kafka is a tool that helps different parts of a system send and receive real-time data as messages. For example, when a user makes a payment, the backend can publish this event to Kafka, and other systems (like fraud check, logs, etc.) can consume it.

4. What is Dependency Injection in Spring Boot?

Answer:
Dependency Injection means giving an object everything it needs (its dependencies) from outside, instead of creating those things itself. In Spring Boot, you can use @Autowired to do this. It makes the code cleaner and easier to test.

5. What is a REST API and how do you create one in Spring Boot?

Answer:
REST API allows two systems to communicate over HTTP (like your browser and a website). In Spring Boot, you can create a REST API using @RestController and @GetMapping.

Example:

java

@RestController
public class HelloController {
@GetMapping("/hello")
public String hello() {
return "Hi from Visa API!";
}
}


6. What is the use of JOIN in SQL?

Answer:
JOIN is used to combine rows from two or more tables based on a related column.

• INNER JOIN gives only matched rows.

• LEFT JOIN gives all rows from the left table and matching rows from the right table.

7. What are unit tests and why are they important?

Answer:
Unit tests check small parts of your code (like individual methods) to ensure they work as expected. They help catch bugs early and save time during development. In Java, JUnit is commonly used for writing unit tests.

8. What is the difference between an Abstract Class and an Interface in Java?

Answer:

• Abstract class can have both implemented and unimplemented (abstract) methods.

• Interface only had abstract methods before Java 8, but now it can also have default and static methods.
  Interfaces are better when you want to define behavior that multiple classes should follow.

9. What is Continuous Integration (CI) and how does it help developers?

Answer:
CI is the practice of automatically building and testing your code whenever someone adds new changes. Tools like Jenkins or GitHub Actions check your code early, which helps catch bugs and keeps the codebase stable.

10. How do you explain a backend project you worked on using Java?

Answer:
You can say:
“I created a small inventory management system using Java and Spring Boot. I built REST APIs to add, delete, and update products. I used PostgreSQL for storing data and tested the APIs using JUnit. It helped me learn how to manage backend logic and connect it with the database.”

Bonus Tips for Visa Java Backend Role

1. Practice SQL daily – Focus on SELECT, JOIN, GROUP BY, WHERE.

2. Understand error logs – Know how to read and fix issues.

3. Learn cloud basics – Especially AWS (EC2, S3, Lambda).

4. Speak clearly – Explain your logic while solving problems.

5. Bring important documents – Resume, certificates, notebook, ID.

6. Revise Java basics – OOP, collections, exceptions, threads.

7. Be honest – It’s okay to say “I’ll learn it.”

8. Use GitHub – Upload your code and projects.

9. Read tech trends – Like APIs, microservices, payments.

10. Stay calm – A fresh mind performs better