Spring Boot interview questions

What is Spring Framework? How is it different from Spring Boot?

Easy · Spring Boot, Core Concepts, Fundamentals

Why was Spring Boot introduced? What problems does it solve?

Easy · Spring Boot, Core Concepts, Fundamentals

What are the advantages of using Spring Boot in enterprise applications?

Easy · Spring Boot, Core Concepts, Fundamentals

Explain the differences between Spring, Spring MVC, and Spring Boot.

Easy · Spring Boot, Core Concepts, Fundamentals

How does Spring Boot simplify dependency management?

Easy · Spring Boot, Core Concepts, Dependency Management

What is an embedded server in Spring Boot? Which servers are supported?

Easy · Spring Boot, Core Concepts, Embedded Server

Explain the concept of convention over configuration in Spring Boot.

Easy · Spring Boot, Core Concepts, Fundamentals

What are Spring Boot Starters? Give examples of commonly used ones.

Easy · Spring Boot, Core Concepts, Starters

What are Spring Boot DevTools? Why are they used?

Easy · Spring Boot, Core Concepts, DevTools

How does Spring Boot differ from traditional WAR-based deployments?

Medium · Spring Boot, Core Concepts, Deployment

What is Spring Initializr and how does it help in project setup?

Easy · Spring Boot, Core Concepts, Tooling

What is the role of Spring Boot CLI? When is it useful?

Easy · Spring Boot, Core Concepts, Tooling

How does Spring Boot achieve auto-configuration?

Medium · Spring Boot, Core Concepts, Auto-Configuration

What are common application.properties and application.yml configurations?

Easy · Spring Boot, Core Concepts, Properties

What is the difference between application.properties and application.yml?

Easy · Spring Boot, Core Concepts, Properties

Explain Spring Boot's layered architecture.

Medium · Spring Boot, Core Concepts, Architecture

What is the default logging framework used in Spring Boot?

Easy · Spring Boot, Core Concepts, Logging

What are the limitations of Spring Boot?

Medium · Spring Boot, Core Concepts, Fundamentals

How do profiles work in Spring Boot?

Easy · Spring Boot, Core Concepts, Profiles

How do you override default properties in Spring Boot?

Medium · Spring Boot, Core Concepts, Properties

What is Spring AOP? Explain aspects, pointcuts, join points, and advice types (Before, After, Around).

Hard · Spring Boot, Core Concepts, AOP

What are the key changes in Spring Boot 3.x (Jakarta EE, Java 17 baseline, virtual threads, GraalVM native images)?

Medium · Spring Boot, Core Concepts, Spring Boot 3

What does the @SpringBootApplication annotation do internally?

Medium · Spring Boot, Annotations & Config, Core Annotations

Difference between @Component, @Service, @Repository, and @Controller.

Easy · Spring Boot, Annotations & Config, Stereotypes

Explain the use of @Configuration and @Bean annotations.

Easy · Spring Boot, Annotations & Config, Java Config

What is the difference between @ComponentScan and @EnableAutoConfiguration?

Medium · Spring Boot, Annotations & Config, Core Annotations

How does @ConditionalOnProperty work in Spring Boot?

Medium · Spring Boot, Annotations & Config, Conditional Beans

Explain the purpose of @EnableConfigurationProperties and @ConfigurationProperties.

Medium · Spring Boot, Annotations & Config, Properties

What is the difference between @Value and @ConfigurationProperties?

Medium · Spring Boot, Annotations & Config, Properties

How does Spring Boot handle externalized configuration?

Medium · Spring Boot, Annotations & Config, Externalized Config

Explain @Import and when to use it.

Medium · Spring Boot, Annotations & Config, Java Config

What does @EnableScheduling do? Provide an example.

Easy · Spring Boot, Annotations & Config, Scheduling

Difference between @RestController and @Controller in Spring Boot.

Easy · Spring Boot, Annotations & Config, Spring MVC

What is the use of @EnableAsync in Spring Boot?

Medium · Spring Boot, Annotations & Config, Async

Explain the @Lazy annotation in Spring.

Medium · Spring Boot, Annotations & Config, Bean Initialization

Difference between @Primary and @Qualifier annotations.

Medium · Spring Boot, Annotations & Config, Bean Selection

What is the use of @Profile in Spring Boot?

Easy · Spring Boot, Annotations & Config, Profiles

How does @Scope annotation work in Spring Boot?

Medium · Spring Boot, Annotations & Config, Bean Scopes

What is @EnableTransactionManagement?

Medium · Spring Boot, Annotations & Config, Transactions

What is the role of @PropertySource annotation?

Easy · Spring Boot, Annotations & Config, Properties

What is the difference between @ImportResource and @Import?

Medium · Spring Boot, Annotations & Config, Java Config

Explain @EnableJpaRepositories and its usage.

Medium · Spring Boot, Annotations & Config, JPA

How does Spring Boot caching work? Explain @EnableCaching, @Cacheable, @CachePut, and @CacheEvict.

Medium · Spring Boot, Annotations & Config, Caching

What is Dependency Injection (DI) in Spring? Why is it important?

Easy · Spring Boot, DI & Bean Lifecycle, Dependency Injection

What are the different types of Dependency Injection in Spring?

Easy · Spring Boot, DI & Bean Lifecycle, Dependency Injection

What is the difference between constructor injection and setter injection?

Easy · Spring Boot, DI & Bean Lifecycle, Dependency Injection

Which injection method is preferred in Spring and why?

Medium · Spring Boot, DI & Bean Lifecycle, Dependency Injection

How does Spring manage the lifecycle of a bean?

Medium · Spring Boot, DI & Bean Lifecycle, Bean Lifecycle

What is the role of the BeanFactory interface?

Medium · Spring Boot, DI & Bean Lifecycle, IoC Container

Difference between ApplicationContext and BeanFactory.

Medium · Spring Boot, DI & Bean Lifecycle, IoC Container

What are the different bean scopes available in Spring?

Easy · Spring Boot, DI & Bean Lifecycle, Bean Scopes

How do you create a prototype-scoped bean?

Easy · Spring Boot, DI & Bean Lifecycle, Bean Scopes

What is the default bean scope in Spring Boot?

Easy · Spring Boot, DI & Bean Lifecycle, Bean Scopes

Explain the difference between singleton bean and prototype bean.

Medium · Spring Boot, DI & Bean Lifecycle, Bean Scopes

What is the role of @PostConstruct and @PreDestroy annotations?

Easy · Spring Boot, DI & Bean Lifecycle, Bean Lifecycle

How do you define custom initialization and destruction methods for beans?

Medium · Spring Boot, DI & Bean Lifecycle, Bean Lifecycle

What are BeanPostProcessor and BeanFactoryPostProcessor?

Hard · Spring Boot, DI & Bean Lifecycle, Bean Lifecycle

What is the difference between @Autowired and @Inject?

Easy · Spring Boot, DI & Bean Lifecycle, Dependency Injection

What is circular dependency in Spring? How is it handled?

Hard · Spring Boot, DI & Bean Lifecycle, Dependency Injection

Difference between field injection, setter injection, and constructor injection.

Medium · Spring Boot, DI & Bean Lifecycle, Dependency Injection

What is @DependsOn annotation in Spring?

Medium · Spring Boot, DI & Bean Lifecycle, Bean Initialization

How do you create lazy-initialized beans in Spring Boot?

Medium · Spring Boot, DI & Bean Lifecycle, Bean Initialization

Explain the lifecycle phases of a Spring bean with example.

Hard · Spring Boot, DI & Bean Lifecycle, Bean Lifecycle

What is auto-configuration in Spring Boot? How does it work?

Medium · Spring Boot, Auto-Config & Starters, Auto-Configuration

What is the role of spring.factories in auto-configuration?

Hard · Spring Boot, Auto-Config & Starters, Auto-Configuration

What is the difference between @EnableAutoConfiguration and @SpringBootApplication?

Medium · Spring Boot, Auto-Config & Starters, Auto-Configuration

How do you exclude an auto-configuration class in Spring Boot?

Easy · Spring Boot, Auto-Config & Starters, Auto-Configuration

What is the purpose of META-INF/spring.factories file?

Medium · Spring Boot, Auto-Config & Starters, spring.factories

How do you create a custom auto-configuration in Spring Boot?

Hard · Spring Boot, Auto-Config & Starters, Auto-Configuration

What is the difference between @ConditionalOnClass and @ConditionalOnMissingBean?

Medium · Spring Boot, Auto-Config & Starters, Conditional Beans

What is @ConditionalOnProperty and when would you use it?

Medium · Spring Boot, Auto-Config & Starters, Conditional Beans

Explain @ConditionalOnResource and its use case.

Medium · Spring Boot, Auto-Config & Starters, Conditional Beans

What are Spring Boot Starter dependencies?

Easy · Spring Boot, Auto-Config & Starters, Starters

Give examples of commonly used Spring Boot Starter dependencies.

Easy · Spring Boot, Auto-Config & Starters, Starters

How do Spring Boot Starters simplify dependency management?

Easy · Spring Boot, Auto-Config & Starters, Starters

What is the difference between spring-boot-starter-web and spring-boot-starter-webflux?

Medium · Spring Boot, Auto-Config & Starters, Starters

What is spring-boot-starter-data-jpa and what does it provide?

Easy · Spring Boot, Auto-Config & Starters, Starters

Explain the role of spring-boot-starter-security.

Easy · Spring Boot, Auto-Config & Starters, Starters

What is the purpose of spring-boot-starter-test?

Easy · Spring Boot, Auto-Config & Starters, Starters

How do you create a custom Spring Boot Starter?

Hard · Spring Boot, Auto-Config & Starters, Custom Starters

What are the advantages of custom Spring Boot Starters?

Medium · Spring Boot, Auto-Config & Starters, Custom Starters

How do you debug issues with auto-configuration in Spring Boot?

Medium · Spring Boot, Auto-Config & Starters, Auto-Configuration

What is the role of spring-boot-autoconfigure module?

Medium · Spring Boot, Auto-Config & Starters, Auto-Configuration

What is Spring Data JPA and how is it different from Hibernate?

Easy · Spring Boot, JPA & Transactions, JPA

What are the advantages of using Spring Data JPA?

Easy · Spring Boot, JPA & Transactions, JPA

What is the role of JpaRepository interface?

Easy · Spring Boot, JPA & Transactions, Repositories

Difference between CrudRepository, PagingAndSortingRepository, and JpaRepository.

Easy · Spring Boot, JPA & Transactions, Repositories

How do you define custom query methods in Spring Data JPA?

Medium · Spring Boot, JPA & Transactions, Query Methods

What is the difference between JPQL and native SQL queries?

Medium · Spring Boot, JPA & Transactions, Queries

How do you use @Query annotation in Spring Data JPA?

Medium · Spring Boot, JPA & Transactions, Queries

What is the difference between getOne() and findById()?

Medium · Spring Boot, JPA & Transactions, Repositories

Difference between save() and saveAndFlush().

Medium · Spring Boot, JPA & Transactions, Repositories

What are derived query methods in Spring Data JPA?

Easy · Spring Boot, JPA & Transactions, Query Methods

What is optimistic locking vs pessimistic locking in JPA?

Hard · Spring Boot, JPA & Transactions, Locking

What is the role of @Transactional annotation in Spring Boot?

Medium · Spring Boot, JPA & Transactions, Transactions

Difference between declarative and programmatic transaction management.

Medium · Spring Boot, JPA & Transactions, Transactions

How do you configure transaction propagation in Spring?

Medium · Spring Boot, JPA & Transactions, Transactions

What is the difference between REQUIRED, REQUIRES_NEW, and MANDATORY propagation levels?

Hard · Spring Boot, JPA & Transactions, Transactions

What is the role of isolation levels in transactions?

Medium · Spring Boot, JPA & Transactions, Isolation Levels

Explain READ_COMMITTED, REPEATABLE_READ, and SERIALIZABLE isolation levels.

Hard · Spring Boot, JPA & Transactions, Isolation Levels

What is dirty read, non-repeatable read, and phantom read?

Medium · Spring Boot, JPA & Transactions, Isolation Levels

How do you roll back transactions in Spring Boot?

Medium · Spring Boot, JPA & Transactions, Transactions

What is the difference between rollbackFor and noRollbackFor in @Transactional?

Medium · Spring Boot, JPA & Transactions, Transactions

What is the N+1 query problem in JPA and how do you fix it?

Hard · Spring Boot, JPA & Transactions, JPA

How do you create a REST API in Spring Boot?

Easy · Spring Boot, REST APIs, Controllers

Difference between @Controller and @RestController.

Easy · Spring Boot, REST APIs, Controllers

What is the role of @RequestMapping annotation?

Easy · Spring Boot, REST APIs, Request Mapping

Difference between @GetMapping, @PostMapping, @PutMapping, @DeleteMapping, and @PatchMapping.

Easy · Spring Boot, REST APIs, Request Mapping

How do you pass path variables in Spring Boot REST APIs?

Easy · Spring Boot, REST APIs, Request Mapping

What is the difference between @RequestParam and @PathVariable?

Easy · Spring Boot, REST APIs, Request Mapping

How do you send and receive JSON in Spring Boot?

Easy · Spring Boot, REST APIs, JSON

What is the role of @RequestBody annotation?

Easy · Spring Boot, REST APIs, JSON

What is the role of @ResponseEntity?

Easy · Spring Boot, REST APIs, Controllers

How do you implement global exception handling in Spring Boot?

Medium · Spring Boot, REST APIs, Exception Handling

What is the use of @ControllerAdvice?

Medium · Spring Boot, REST APIs, Exception Handling

What is the difference between @ExceptionHandler and @ControllerAdvice?

Medium · Spring Boot, REST APIs, Exception Handling

How do you perform input validation in Spring Boot?

Medium · Spring Boot, REST APIs, Validation

What is the role of @Valid and @Validated annotations?

Medium · Spring Boot, REST APIs, Validation

How do you define custom validation constraints?

Hard · Spring Boot, REST APIs, Validation

What is the difference between checked and unchecked exceptions in REST APIs?

Medium · Spring Boot, REST APIs, Exception Handling

How do you implement versioning in REST APIs (URI, Query Params, Headers)?

Medium · Spring Boot, REST APIs, API Design

How do you implement HATEOAS in Spring Boot?

Hard · Spring Boot, REST APIs, API Design

How do you implement pagination and sorting in REST APIs?

Medium · Spring Boot, REST APIs, API Design

How do you secure REST APIs in Spring Boot?

Medium · Spring Boot, REST APIs, API Security

When would you choose REST over GraphQL?

Easy · Spring Boot, REST APIs, API Design

What is Spring Security and why is it used?

Easy · Spring Boot, Spring Security, Security Basics

Difference between authentication and authorization.

Easy · Spring Boot, Spring Security, Security Basics

How do you configure basic authentication in Spring Boot?

Easy · Spring Boot, Spring Security, Authentication

What is the role of UserDetailsService in Spring Security?

Medium · Spring Boot, Spring Security, Authentication

What is the difference between GrantedAuthority and Role?

Medium · Spring Boot, Spring Security, Authorization

How do you secure REST APIs with role-based access in Spring Boot?

Medium · Spring Boot, Spring Security, Authorization

What is CSRF protection? How does Spring Security handle it?

Medium · Spring Boot, Spring Security, Web Security

What is JWT (JSON Web Token)? How is it used in Spring Security?

Medium · Spring Boot, Spring Security, JWT

What are the advantages of JWT over session-based authentication?

Medium · Spring Boot, Spring Security, JWT

How do you implement JWT authentication in Spring Boot?

Hard · Spring Boot, Spring Security, JWT

What is the role of filters in Spring Security?

Medium · Spring Boot, Spring Security, Filter Chain

Difference between OncePerRequestFilter and GenericFilterBean.

Hard · Spring Boot, Spring Security, Filter Chain

What is OAuth2 and how does it work with Spring Security?

Medium · Spring Boot, Spring Security, OAuth2

Difference between OAuth2 authorization code flow, implicit flow, and client credentials flow.

Hard · Spring Boot, Spring Security, OAuth2

How do you implement OAuth2 login in Spring Boot?

Hard · Spring Boot, Spring Security, OAuth2

What is the difference between @EnableWebSecurity and WebSecurityConfigurerAdapter?

Medium · Spring Boot, Spring Security, Security Config

How do you customize Spring Security configuration in Spring Boot 3.x (no WebSecurityConfigurerAdapter)?

Hard · Spring Boot, Spring Security, Security Config

What is stateless authentication and why is it important for REST APIs?

Medium · Spring Boot, Spring Security, Stateless Auth

How do you secure endpoints with method-level security (@PreAuthorize, @Secured)?

Medium · Spring Boot, Spring Security, Authorization

What is the difference between symmetric and asymmetric encryption in JWT?

Hard · Spring Boot, Spring Security, JWT

What are microservices and how are they different from monoliths?

Easy · Spring Boot, Microservices, Architecture

What are the main advantages of microservices architecture?

Easy · Spring Boot, Microservices, Architecture

How do you implement service discovery using Eureka?

Medium · Spring Boot, Microservices, Service Discovery

What is the role of Netflix Eureka in Spring Cloud?

Easy · Spring Boot, Microservices, Service Discovery

How do you configure a Spring Boot application as a Eureka client?

Medium · Spring Boot, Microservices, Service Discovery

What is Spring Cloud Config Server? How is it used?

Medium · Spring Boot, Microservices, Config Server

How do you secure communication between Config Server and microservices?

Hard · Spring Boot, Microservices, Config Server

What is API Gateway? Difference between Zuul and Spring Cloud Gateway.

Medium · Spring Boot, Microservices, API Gateway

How do you implement request routing with Spring Cloud Gateway?

Medium · Spring Boot, Microservices, API Gateway

What is Feign Client and why is it used in microservices?

Easy · Spring Boot, Microservices, Service Communication

Difference between Feign Client and RestTemplate.

Medium · Spring Boot, Microservices, Service Communication

What is load balancing in microservices? How does Ribbon work?

Medium · Spring Boot, Microservices, Load Balancing

What is Resilience4j and how does it improve fault tolerance?

Medium · Spring Boot, Microservices, Resilience

Difference between Circuit Breaker, Bulkhead, Retry, and Rate Limiter patterns.

Hard · Spring Boot, Microservices, Resilience

How do you implement a circuit breaker in Spring Boot with Resilience4j?

Hard · Spring Boot, Microservices, Resilience

What is Hystrix? Why is Resilience4j preferred over Hystrix?

Medium · Spring Boot, Microservices, Resilience

What is distributed tracing? How do you implement it in Spring Boot?

Medium · Spring Boot, Microservices, Distributed Tracing

What are Sleuth and Zipkin? How do they work with Spring Boot?

Medium · Spring Boot, Microservices, Distributed Tracing

How do you handle centralized logging in microservices?

Medium · Spring Boot, Microservices, Logging

What are the best practices for designing Spring Boot microservices?

Hard · Spring Boot, Microservices, Best Practices

How do you deploy a Spring Boot application to AWS?

Medium · Spring Boot, Cloud & AWS, Deployment

What is the difference between AWS Elastic Beanstalk and ECS for Spring Boot apps?

Medium · Spring Boot, Cloud & AWS, Deployment

How do you connect a Spring Boot application to AWS RDS?

Easy · Spring Boot, Cloud & AWS, RDS

What are the best practices for securing AWS RDS credentials in Spring Boot?

Medium · Spring Boot, Cloud & AWS, Secrets Management

How do you use AWS Parameter Store or Secrets Manager with Spring Boot?

Medium · Spring Boot, Cloud & AWS, Secrets Management

How do you integrate Spring Boot with AWS S3?

Easy · Spring Boot, Cloud & AWS, S3

How do you upload and download files to S3 using Spring Boot?

Medium · Spring Boot, Cloud & AWS, S3

What is the difference between S3 and EFS? When to use each?

Medium · Spring Boot, Cloud & AWS, S3

How do you integrate Spring Boot with AWS SQS?

Medium · Spring Boot, Cloud & AWS, SQS

Difference between SQS standard and FIFO queues.

Medium · Spring Boot, Cloud & AWS, SQS

How do you integrate Spring Boot with AWS SNS?

Medium · Spring Boot, Cloud & AWS, SNS

What is the difference between SQS and SNS?

Easy · Spring Boot, Cloud & AWS, SQS

How do you integrate Spring Boot with AWS Lambda?

Hard · Spring Boot, Cloud & AWS, Serverless

What are the best practices for building serverless applications with Spring Boot on AWS?

Hard · Spring Boot, Cloud & AWS, Serverless

How do you implement distributed caching with AWS ElastiCache (Redis/Memcached)?

Medium · Spring Boot, Cloud & AWS, Caching

How do you configure Spring Boot for AWS DynamoDB?

Medium · Spring Boot, Cloud & AWS, DynamoDB

Difference between RDS and DynamoDB for Spring Boot apps.

Medium · Spring Boot, Cloud & AWS, RDS

How do you secure Spring Boot applications running on AWS (IAM roles, VPCs, security groups)?

Hard · Spring Boot, Cloud & AWS, Cloud Security

What is AWS API Gateway and how do you integrate it with Spring Boot microservices?

Medium · Spring Boot, Cloud & AWS, API Gateway

How do you monitor and scale Spring Boot microservices on AWS?

Hard · Spring Boot, Cloud & AWS, Scaling

What are the different types of testing in Spring Boot?

Easy · Spring Boot, Testing, Test Strategy

Difference between unit test and integration test.

Easy · Spring Boot, Testing, Test Strategy

How do you write a simple JUnit 5 test in Spring Boot?

Easy · Spring Boot, Testing, JUnit 5

How do you mock dependencies using Mockito?

Easy · Spring Boot, Testing, Mockito

Difference between @Mock and @MockBean in Spring Boot tests.

Medium · Spring Boot, Testing, Mockito

What is the role of @SpringBootTest annotation?

Medium · Spring Boot, Testing, Integration Testing

What is @DataJpaTest used for?

Medium · Spring Boot, Testing, Test Slices

How do you test REST controllers in Spring Boot?

Medium · Spring Boot, Testing, MockMvc

What is MockMvc and how is it used?

Medium · Spring Boot, Testing, MockMvc

Difference between WebMvcTest and SpringBootTest.

Medium · Spring Boot, Testing, Test Slices

How do you test service layer components?

Easy · Spring Boot, Testing, Unit Testing

How do you test exception handling in Spring Boot?

Medium · Spring Boot, Testing, MockMvc

What are Testcontainers? Why are they useful?

Medium · Spring Boot, Testing, Testcontainers

How do you use Testcontainers with Spring Boot?

Hard · Spring Boot, Testing, Testcontainers

How do you test with an in-memory database like H2?

Easy · Spring Boot, Testing, Integration Testing

What is the role of embedded Kafka/RabbitMQ in integration tests?

Hard · Spring Boot, Testing, Integration Testing

How do you measure code coverage in Spring Boot tests?

Easy · Spring Boot, Testing, Code Coverage

How do you test asynchronous methods in Spring Boot?

Hard · Spring Boot, Testing, Async

How do you run Spring Boot tests in parallel?

Hard · Spring Boot, Testing, Test Performance

What are best practices for writing maintainable Spring Boot tests?

Medium · Spring Boot, Testing, Best Practices

What is Spring Boot Actuator and why is it used?

Easy · Spring Boot, Actuator & Observability, Actuator

What are the default Actuator endpoints available in Spring Boot?

Easy · Spring Boot, Actuator & Observability, Actuator

How do you enable and secure Actuator endpoints?

Medium · Spring Boot, Actuator & Observability, Actuator

How do you create custom Actuator endpoints?

Medium · Spring Boot, Actuator & Observability, Actuator

What is Micrometer in Spring Boot?

Medium · Spring Boot, Actuator & Observability, Metrics

How do you integrate Spring Boot with Prometheus?

Medium · Spring Boot, Actuator & Observability, Metrics

How do you integrate Spring Boot with Grafana dashboards?

Medium · Spring Boot, Actuator & Observability, Metrics

How do you configure distributed tracing with Spring Cloud Sleuth?

Medium · Spring Boot, Actuator & Observability, Distributed Tracing

What is Zipkin and how does it integrate with Spring Boot?

Medium · Spring Boot, Actuator & Observability, Distributed Tracing

How do you send Spring Boot logs to ELK stack (Elasticsearch, Logstash, Kibana)?

Medium · Spring Boot, Actuator & Observability, Logging

What are the best practices for monitoring microservices in production?

Hard · Spring Boot, Actuator & Observability, Best Practices

What is the health check endpoint and why is it important in cloud deployments?

Easy · Spring Boot, Actuator & Observability, Actuator

How do you configure metrics for JVM memory, threads, and garbage collection?

Medium · Spring Boot, Actuator & Observability, Metrics

How do you enable request/response tracing in Spring Boot?

Medium · Spring Boot, Actuator & Observability, Actuator

How do you integrate Spring Boot with centralized logging frameworks?

Medium · Spring Boot, Actuator & Observability, Logging

What is OpenTelemetry and how does it relate to Spring Boot observability?

Hard · Spring Boot, Actuator & Observability, OpenTelemetry

How do you configure graceful shutdown in Spring Boot applications?

Medium · Spring Boot, Actuator & Observability, Production Readiness

What are performance tuning tips for Spring Boot in production?

Hard · Spring Boot, Actuator & Observability, Performance

How do you handle thread pool tuning in Spring Boot?

Hard · Spring Boot, Actuator & Observability, Performance

What are the common production pitfalls in Spring Boot and how to avoid them?

Hard · Spring Boot, Actuator & Observability, Production Readiness

How do virtual threads work in Spring Boot 3.2+? When should you enable them?

Medium · Spring Boot, Modern Spring Boot 3.x, Virtual Threads

What is Spring Native and GraalVM native image compilation? Trade-offs vs JVM deployment?

Hard · Spring Boot, Modern Spring Boot 3.x, Spring Native

Compare RestTemplate, WebClient, and RestClient in Spring Boot. When do you use each?

Medium · Spring Boot, Modern Spring Boot 3.x, HTTP Clients

How does Micrometer Tracing replace Spring Cloud Sleuth in Spring Boot 3?

Medium · Spring Boot, Modern Spring Boot 3.x, Distributed Tracing

What is Spring Cloud LoadBalancer and how does it replace Netflix Ribbon?

Medium · Spring Boot, Modern Spring Boot 3.x, Load Balancing

How does AutoConfiguration.imports differ from META-INF/spring.factories in Spring Boot 3?

Medium · Spring Boot, Modern Spring Boot 3.x, Auto-Configuration

How do you enable RFC 7807 Problem Details for API errors in Spring Boot?

Easy · Spring Boot, Modern Spring Boot 3.x, REST APIs

Why use Java records as DTOs in Spring Boot REST APIs?

Easy · Spring Boot, Modern Spring Boot 3.x, REST APIs

How do declarative HTTP clients work with @HttpExchange in Spring Boot 3?

Medium · Spring Boot, Modern Spring Boot 3.x, HTTP Clients

How do Spring application events work? Explain @EventListener and async events.

Medium · Spring Boot, Messaging & Events, Senior

How do you integrate Apache Kafka with Spring Boot?

Medium · Spring Boot, Messaging & Events, Kafka

How do you integrate RabbitMQ with Spring Boot using Spring AMQP?

Medium · Spring Boot, Messaging & Events, RabbitMQ

What is the transactional outbox pattern in Spring Boot microservices?

Hard · Spring Boot, Messaging & Events, Architect

How do you manage database schema migrations with Flyway or Liquibase in Spring Boot?

Medium · Spring Boot, JPA & Transactions, Database Migrations

How do you tune HikariCP connection pool settings in Spring Boot?

Medium · Spring Boot, JPA & Transactions, Connection Pooling

How do you implement multitenancy in Spring Boot (schema-per-tenant vs discriminator column)?

Hard · Spring Boot, JPA & Transactions, Multitenancy

How do you configure CORS in Spring Boot for browser-based clients?

Easy · Spring Boot, REST APIs, CORS

How do you document REST APIs with OpenAPI/Springdoc in Spring Boot?

Easy · Spring Boot, REST APIs, OpenAPI

What is the difference between Servlet Filter, HandlerInterceptor, and Spring Security filter chain?

Medium · Spring Boot, REST APIs, Senior

Explain the Spring MVC request lifecycle from HTTP request to response.

Medium · Spring Boot, REST APIs, Spring MVC

How do you design idempotent REST APIs in Spring Boot?

Hard · Spring Boot, REST APIs, Architect

How do you implement API rate limiting in Spring Boot?

Hard · Spring Boot, REST APIs, Architect

How do you handle file uploads in Spring Boot REST APIs?

Easy · Spring Boot, REST APIs, Fresher

What is content negotiation in Spring MVC? How do produces and consumes work?

Easy · Spring Boot, REST APIs, Fresher

How do you build a GraphQL API with Spring Boot?

Medium · Spring Boot, REST APIs, GraphQL

What is Spring WebFlux? When should you choose reactive over traditional Spring MVC?

Hard · Spring Boot, Reactive & Performance, WebFlux

What is Spring Batch and when do you use it in enterprise applications?

Medium · Spring Boot, Reactive & Performance, Spring Batch

What is Spring Modulith and how does it help structure modular monoliths?

Hard · Spring Boot, Architecture & Deployment, Spring Modulith

Compare layered architecture vs hexagonal (ports & adapters) in Spring Boot projects.

Medium · Spring Boot, Architecture & Deployment, Architect

What are best practices for Dockerizing Spring Boot applications?

Easy · Spring Boot, Architecture & Deployment, Docker

How do you deploy and operate Spring Boot apps on Kubernetes?

Hard · Spring Boot, Architecture & Deployment, Kubernetes

How do you achieve zero-downtime deployments for Spring Boot microservices?

Hard · Spring Boot, Architecture & Deployment, Architect

How do you implement the Saga pattern for distributed transactions in Spring Boot?

Hard · Spring Boot, Microservices, Saga

How would you implement CQRS in a Spring Boot application?

Hard · Spring Boot, Architecture & Deployment, CQRS

How does Spring AI integrate LLMs into Spring Boot applications?

Medium · Spring Boot, Modern Spring Boot 3.x, Spring AI