TCS Java | Spring Boot | Microservices | 4 Years | Selected | Mock Interview

Summary

In this interview, a Java developer with 4.2 years of experience discusses their expertise in Spring Boot and microservices, particularly within a banking domain. They detail their project's architecture, including Angular UI, microservices, Eureka for service discovery, and Hystrix for fault tolerance. The conversation covers Spring Boot advantages, dependency injection, common annotations, exception handling, HTTP status codes, database connectivity, transaction management, and microservices communication. The candidate expresses eagerness to learn cloud deployment and expand their skill set.

Takeaways

• 😀 The interviewee has 4.2 years of experience as a Java developer with expertise in Java, Spring Boot, and microservices.
• 👨‍💻 The interviewee is currently working in a banking domain with a microservice-based architecture, utilizing technologies like Angular for UI and Eureka for service discovery.
• 🔧 Spring Boot's advantages over Spring include simplified configuration, embedded servers, and annotation-based dependency management.
• 📚 Dependency injection in Spring helps manage the bean lifecycle by decoupling bean creation and configuration, with techniques like constructor injection and setter injection.
• 🏷 Common Spring Boot annotations used by the interviewee include `@SpringBootApplication`, `@RestController`, and various `@RequestMapping` methods for handling HTTP requests.
• 🛑 The interviewee explained the use of a Global Exception Handler in Spring Boot to manage exceptions at the REST layer, utilizing `@ExceptionHandler` and `@RestControllerAdvice`.
• 📈 The understanding of HTTP status codes such as 200, 404, 401, 403, and 500 was demonstrated, indicating the types of responses used in their application.
• 🔌 The process of designing REST APIs, connecting to databases, and fetching data using JPA repositories and service layers was explained.
• 🔄 The interviewee discussed transaction management in Spring Boot using the `@Transactional` annotation, typically applied at the service layer.
• 💡 Microservices were described as small, independent services performing specific business functions, with examples from the interviewee's application such as API Gateway, Eureka server, and various domain-specific services.
• 🔗 Communication between microservices was discussed, including using REST templates for direct calls and message brokers like RabbitMQ for asynchronous communication.

Q & A

What is the primary focus of the interview?

The primary focus of the interview is to assess the candidate's knowledge and experience with Java, Spring Boot, and microservices, as indicated in their resume.

What is the candidate's experience in the field?

The candidate has approximately 4.2 years of experience working as a Java developer.

What is the domain the candidate is currently working in?

The candidate is currently working in the banking domain.

What architecture is the candidate's project based on?

The project is based on a microservices architecture.

What does the candidate consider as the main advantage of Spring Boot over Spring?

The main advantage is the simplified configuration, allowing for quicker setup and deployment of applications with embedded servers and streamlined dependency management.

Can you explain the concept of Dependency Injection in Spring as described by the candidate?

Dependency Injection in Spring is the process of injecting a dependency into a class, often through constructor injection or setter injection, which helps in decoupling bean creation and configuration, thus managing the bean lifecycle.

What are some common annotations used in Spring Boot applications according to the candidate?

Some common annotations include `@SpringBootApplication`, `@RestController`, `@GetMapping`, `@PostMapping`, `@PutMapping`, `@DeleteMapping`, and `@Autowired`.

How does the candidate handle exceptions in a Spring Boot application?

The candidate uses a Global Exception Handler class annotated with `@ExceptionHandler` to manage exceptions at the REST layer, returning appropriate responses with status codes.

What is the candidate's understanding of microservices?

Microservices are small, independent services designed to perform specific business functions within a larger application, each operating autonomously and communicating with others as needed.

How do microservices communicate with each other in the candidate's application?

Microservices communicate with each other using REST templates to make API calls to endpoints or through message brokers like RabbitMQ or Kafka for asynchronous communication.

What is the role of service discovery in the candidate's microservices architecture?

Service discovery is used to identify and register the instances of services within the architecture, allowing services to locate and communicate with each other through an API Gateway.

How does the candidate handle database schema changes in their applications?

The candidate suggests using tools like Flyway or Liquibase to manage database schema changes through migration scripts, which can be automated as part of the CI/CD pipeline.

What is the candidate's approach to choosing between SQL and NoSQL databases?

The candidate would choose based on the data model, consistency requirements, and complexity, opting for SQL databases for structured data and NoSQL for unstructured or semi-structured data.

What is the candidate's understanding of Java 8 streams?

Java 8 streams are pipelines used to perform operations on a sequence of elements, allowing for operations like filtering, mapping, and reducing through intermediate and terminal operations.

How does the candidate describe the use of unique constraints in databases?

Unique constraints ensure that the values in a specified column are unique across all records in a database table, preventing duplicate entries.

What cloud provider does the candidate's team use for deploying applications?

The candidate is not certain about the specific cloud provider, as deployment is handled by the build and release team, but mentions that their applications are deployed to the cloud.