Interviews feel totally different when you walk in with clarity. Especially in backend and enterprise engineering roles, employers instantly know who has real project experience and who memorized a few definitions the night before. Spring Boot Interview Questions are more than just a checklist — they’re your passport to a thriving backend or full-stack career in 2026. In a job market where demand for robust, scalable, cloud-native applications is skyrocketing, mastering Spring Boot can seriously set you apart.

Here’s why this skill matters now more than ever:

• Java (and frameworks built on it) remains the backbone of enterprise and large-scale systems globally. Many backend job listings in India and beyond list Java + Spring Boot as mandatory skills. (KaaShiv InfoTech)
• A 2024/2025 global developer survey reports that Spring/Spring Boot is the #1 Java framework, used by 63–66% of all Java professionals for cloud-native and enterprise apps (Eclipse Foundation).
• The shift toward microservices, cloud-native infrastructure, and scalable REST APIs has made Spring Boot one of the most preferred frameworks for building reliable backend systems (or full-stack backends + frontend). (Medium)
• For full-stack developers, combining Spring Boot backend skills with a modern frontend stack dramatically increases your job-readiness — many contemporary roles expect developers to handle both ends.

If you invest a little time today to prepare well — understand why Spring Boot matters, know its common interview questions — you’re not just preparing for one interview. You’re investing in a future-proof, high-demand skillset that many employers will value for years to come.

Below — a curated list of 25 typical Spring Boot interview questions that recruiters still ask often in 2026. No fluff. No filler. Just what you need to know.

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🔥 Top Spring Boot Interview Questions (2026)

1. What is Spring Boot?

Answer:
Spring Boot is an open-source, Java-based framework that simplifies building standalone, production-ready applications. It is built on top of the Spring framework and removes the need for complex configuration. Spring Boot also provides embedded servers like Tomcat and Jetty, so applications run easily without deploying them to an external server.

Why interviewers ask this:
To check if you understand why Spring Boot exists, not just what it is.

🧠 What impresses interviewers:
A clarity + productivity angle.
👉 “Spring Boot removes 80% of setup work by auto-configuring your app and providing embedded servers — making development and deployment faster.”

🚫 Common mistake:
“Saying ‘Spring Boot is a framework to build Java apps’”—too generic.

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2. How is Spring Boot different from Spring?

Answer:
Spring requires a lot of manual configuration, XML setup, dispatcher configuration, and external server deployment.
Spring Boot removes all this by providing:

• Auto-configuration
• Starter dependencies
• Embedded servers
• Production-ready features (Actuator)

Spring = flexible but configuration-heavy
Spring Boot = ready-to-run with minimal setup

Why interviewers ask:
To see if you understand what problem Spring Boot solves.

🧠 Impress them:
Show clarity.
👉 “Spring Boot reduces configuration and speeds up development.”

🚫 Mistake:
Saying “Spring Boot is faster than Spring.”

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3. What is Auto-Configuration in Spring Boot?

Answer:
Auto-configuration automatically sets up Spring components based on what is present on the classpath. For example, if spring-boot-starter-web is added, Spring Boot automatically configures MVC, Tomcat, and JSON handling.

Why interviewers ask:
To test whether you understand how Boot configures things behind the scenes.

🧠 Impress:
👉 “Auto-configuration is conditional. It only applies if a bean doesn’t already exist.”

🚫 Mistake:
Calling it “automatic configuration” without explaining how it decides.

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4. What are Spring Boot Starters?

Answer:
Starters are predefined dependency packages that bring all required libraries for a specific feature (web, data JPA, security, etc.) so you don’t need to manage versions manually.

Why interviewers ask:
To check your understanding of dependency simplification.

🧠 Impress:
👉 “Starters avoid dependency conflicts and make setup easier.”

🚫 Mistake:
“Starters are just dependencies.”

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5. What is an Embedded Server in Spring Boot?

Answer:
An embedded server is a server (like Tomcat, Jetty, or Undertow) included inside the application JAR. This allows the application to run directly using java -jar, without deploying to an external app server.

Why interviewers ask:
To see if you know how Boot simplifies deployment.

🧠 Impress:
👉 “Embedded servers make Spring Boot ideal for microservices.”

🚫 Mistake:
Saying “Tomcat is inside Spring Boot” without explaining the benefit.

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6. What is Spring Boot Actuator?

Answer:
Spring Boot Actuator provides production-ready endpoints that give information about application health, metrics, memory, environment, logs, and more.

Why interviewers ask:
Because Actuator is heavily used in real-world production systems.

🧠 Impress:
👉 “Actuator helps monitor and manage apps in production easily.”

🚫 Mistake:
Just listing endpoints instead of explaining why they are useful.

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7. What is application.properties / application.yml in Spring Boot?

Answer:
These files store application settings such as port numbers, database credentials, logging levels, and custom configurations. Spring Boot loads these properties automatically at startup.

Why interviewers ask:
To check if you understand configuration management.

🧠 Impress:
👉 “These files support profiles for different environments.”

🚫 Mistake:
Calling them “just configuration files” without context.

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8. What are Spring Profiles?

Answer:
Profiles allow you to group and load different configurations for different environments like dev, test, and prod. You can activate a profile using properties or command-line switches.

Why interviewers ask:
Most companies use multi-environment pipelines.

🧠 Impress:
👉 “Profiles help cleanly separate environment-specific settings.”

🚫 Mistake:
“Saying profiles are for separating code.”

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9. How does Spring Boot handle dependency management?

Answer:
Spring Boot uses a parent POM (spring-boot-starter-parent) that comes with pre-defined versions of commonly used libraries. This ensures compatibility and avoids version conflicts.

Why interviewers ask:
To check if you understand how Boot avoids dependency issues.

🧠 Impress:
👉 “Spring Boot uses a BOM (Bill of Materials) to manage dependency versions.”

🚫 Mistake:
“Saying it downloads dependencies automatically.”

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10. What is @SpringBootApplication?

Answer:
@SpringBootApplication is a combination of three annotations:

• @Configuration
• @EnableAutoConfiguration
• @ComponentScan

It marks the main class and triggers component scanning and auto-configuration.

Why interviewers ask:
It’s the core entry point of any Spring Boot application.

🧠 Impress:
👉 “You can also exclude auto-configurations using its exclude attribute.”

🚫 Mistake:
Calling it “the main annotation” without explaining what it contains.

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11. What is the purpose of the Spring Boot CLI?

Answer:
Spring Boot CLI (Command Line Interface) allows you to run and test Spring applications quickly using Groovy scripts. It reduces boilerplate code and speeds up prototyping.

Why interviewers ask:
To check if you know tools that speed up development.

🧠 Impress:
👉 “CLI is great for quickly testing ideas without creating a full project.”

🚫 Mistake:
Confusing CLI with Maven/Gradle.

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12. What are Spring Boot Starters Parent (Parent POM)?

Answer:
The Spring Boot Parent POM provides default configurations like Java version, dependency versions, plugin settings, and build configurations. It standardizes the project structure.

Why interviewers ask:
To check knowledge of project setup and consistency.

🧠 Impress:
👉 “It ensures compatibility across all dependencies using predefined versions.”

🚫 Mistake:
“Saying it is required for every project” — it’s optional.

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13. What is the difference between @Component, @Service, @Repository, and @Controller?

Answer:
All are Spring stereotypes for auto-detection:

• @Component – generic Spring-managed bean
• @Service – business logic layer
• @Repository – DAO layer + exception translation
• @Controller – MVC controller for web requests

Why interviewers ask:
To test architecture understanding.

🧠 Impress:
👉 “They help organize layers and improve code readability.”

🚫 Mistake:
Saying all annotations are the same.

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14. What is the use of @RestController?

Answer:
@RestController combines @Controller and @ResponseBody, returning JSON or XML automatically instead of rendering a view.

Why interviewers ask:
It’s used in almost every Spring Boot API.

🧠 Impress:
👉 “It is the standard annotation for REST APIs.”

🚫 Mistake:
Saying it “creates REST APIs” without explaining how.

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15. What is Spring Initializr?

Answer:
Spring Initializr is a web tool used to generate Spring Boot project structures with selected dependencies, modules, and packaging.

Why interviewers ask:
To check if you know modern project-creation tools.

🧠 Impress:
👉 “It eliminates manual setup and ensures a consistent base structure.”

🚫 Mistake:
Calling it “an IDE tool” — it’s web-based.

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16. How does Spring Boot support externalized configuration?

Answer:
Spring Boot allows configurations through properties, YAML files, environment variables, command-line arguments, and config servers. This helps change settings without modifying code.

Why interviewers ask:
To check DevOps readiness.

🧠 Impress:
👉 “Externalized config makes deployments safer and flexible.”

🚫 Mistake:
Only mentioning application.properties.

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17. What is @EnableAutoConfiguration?

Answer:
This annotation tells Spring Boot to automatically configure beans based on the project’s dependencies and classpath.

Why interviewers ask:
It is one of the core concepts of Spring Boot.

🧠 Impress:
👉 “It activates conditional configurations behind the scenes.”

🚫 Mistake:
Thinking it configures everything unconditionally.

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18. How do you change the default port in Spring Boot?

Answer:
By setting:

server.port=8081

in application.properties (or YAML equivalent).
You can also change it using command-line arguments.

Why interviewers ask:
Simple, but checks basic hands-on familiarity.

🧠 Impress:
👉 Mention multiple methods (properties + command-line).

🚫 Mistake:
Saying “You cannot change it.”

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19. What is the use of @Configuration?

Answer:
@Configuration marks a class as a source of Spring bean definitions. It typically contains methods with @Bean to manually configure components.

Why interviewers ask:
To test your understanding of manual configuration vs. auto-configuration.

🧠 Impress:
👉 “It’s part of Java-based configuration introduced to replace XML.”

🚫 Mistake:
Calling it “just a class annotation.”

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20. What is a Bean in Spring?

Answer:
A Bean is an object managed by the Spring IoC container. Spring creates, initializes, and manages the lifecycle of beans automatically.

Why interviewers ask:
Beans are the foundation of the Spring framework.

🧠 Impress:
👉 “Beans are created and wired using dependency injection.”

🚫 Mistake:
Saying “Beans are objects” — too incomplete.

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21. What is Dependency Injection (DI) in Spring Boot?

Answer:
Dependency Injection is a design pattern where Spring creates objects and provides them to other objects instead of you creating them manually. This reduces tight coupling and improves testability.

Why interviewers ask:
DI is the core concept behind Spring, so they ensure you understand it well.

🧠 Impress:
👉 “Spring manages object creation, wiring, and lifecycle automatically.”

🚫 Mistake:
Saying “DI is passing objects” — too vague.

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22. What is Spring Boot DevTools?

Answer:
Spring Boot DevTools provides features like automatic restart, live reload, and improved development configuration to make development faster and smoother.

Why interviewers ask:
To see if you know tools that improve developer productivity.

🧠 Impress:
👉 “DevTools restarts the application instantly when code changes are detected.”

🚫 Mistake:
Thinking DevTools is used in production — it’s strictly for development.

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23. What is the difference between @RequestBody and @ResponseBody?

Answer:

• @RequestBody — Converts incoming JSON/XML into a Java object.
• @ResponseBody — Converts Java objects into JSON/XML to send back to the client.

Why interviewers ask:
These are basic but essential for REST API development.

🧠 Impress:
👉 “@RestController already includes @ResponseBody by default.”

🚫 Mistake:
Mixing up request and response purposes.

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24. What is the purpose of application.properties vs application.yml?

Answer:
Both store configuration values.

• .properties uses key-value pairs.
• .yml uses a hierarchical structure that is cleaner and more readable for complex settings.

Why interviewers ask:
To check if you understand configuration styles.

🧠 Impress:
👉 “YAML is better for nested settings like security or database configs.”

🚫 Mistake:
Saying YML is “mandatory” — both are equally supported.

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25. How do you enable scheduling in Spring Boot?

Answer:
You enable scheduling by adding the @EnableScheduling annotation and marking methods with @Scheduled.

Why interviewers ask:
Scheduling is common in real applications (cron jobs, cleanup tasks).

🧠 Impress:
👉 Mention cron usage:
@Scheduled(cron = "0 */5 * * * *")

🚫 Mistake:
Thinking scheduling works automatically without enabling it.

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26. What is Spring Data JPA?

Answer:
Spring Data JPA is a Spring module that simplifies working with relational databases. It reduces boilerplate code and provides an easy way to perform CRUD operations using repositories.

Why interviewers ask:
Most real projects use Spring Boot + JPA for database work.

🧠 Impress:
👉 “It builds on top of Hibernate and provides methods without writing SQL.”

🚫 Mistake:
Thinking Spring Data JPA replaces Hibernate — it uses Hibernate internally.

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27. What is the purpose of @Entity in Spring Boot?

Answer:
@Entity marks a class as a database table representation. Its fields become table columns, and instances of the class map to rows.

Why interviewers ask:
To test basic ORM understanding.

🧠 Impress:
👉 “An @Id field is mandatory for every @Entity.”

🚫 Mistake:
Saying @Entity is only used to “store data” — missing the mapping concept.

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28. What is the difference between @PathVariable and @RequestParam?

Answer:

• @PathVariable extracts values from the URL path
  Example: /users/10
• @RequestParam extracts values from query parameters
  Example: /users?id=10

Why interviewers ask:
To check if you understand REST URL design.

🧠 Impress:
👉 Give a simple example of each.

🚫 Mistake:
Saying both do the same job.

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29. What is the use of @Autowired?

Answer:
@Autowired injects dependencies automatically into classes, constructors, or methods. It helps Spring manage wiring between components.

Why interviewers ask:
To check your understanding of DI and bean wiring.

🧠 Impress:
👉 “Constructor-based injection is preferred over field injection.”

🚫 Mistake:
Thinking @Autowired is required everywhere — Spring can auto-detect constructors.

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30. What is the difference between JAR and WAR packaging in Spring Boot?

Answer:

• JAR: Default Spring Boot packaging. Contains embedded server. Run using java -jar.
• WAR: Used when deploying to external application servers like Tomcat or WildFly.

Why interviewers ask:
To check deployment knowledge.

🧠 Impress:
👉 “JARs are preferred for microservices because they run standalone.”

🚫 Mistake:
Saying WAR is obsolete — some enterprises still use it.

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✅ Conclusion

And here’s the truth — Spring Boot has become the default standard for building production-grade Java applications. Whether you aim to work purely as a backend engineer or as a full-stack developer, knowing Spring Boot well gives you a powerful foundation in 2026’s tech world. Companies building scalable APIs, microservices, cloud-native platforms — from fintech to e-commerce to enterprise SaaS to AI platforms— heavily rely on Java + Spring Boot. (Medium)

Companies don’t hire Java developers who just “know annotations.”
They hire developers who can ship reliable systems, understand performance, and explain how Spring Boot works behind the scenes.

You now have the exact questions companies ask today, the patterns recruiters look for, and the type of thinking that makes interviewers say:

“This developer can actually handle real systems.”

By mastering these Spring Boot interview questions — and later experimenting with real projects — you don’t just prepare for interviews.

• You build confidence in designing and delivering backend (or full-stack) systems.
• You align your skills with what the industry currently demands.
• You open doors to better job offers, higher pay, and more future-proof career paths.

So use these questions as more than an interview prep — treat them as the beginning of your Spring Boot journey. Once comfortable, build small projects, integrate frontend, databases, cloud — and you’ll position yourself not just as a candidate, but as the candidate companies want to hire.

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🔗 Related Reads

• Basic Java Interview Questions & Answers
• Top 25 Java Full Stack Developer Interview Questions for Freshers [2026 Guide]
• Experience Java Interview Questions & Answers
• OOPS Interview Questions in Java
• Java – What is final, finally, and finalize?

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