Why Spring Boot?
The default choice for production Java backends, for a reason
Plain Spring gives you dependency injection, AOP, and a huge ecosystem — but wiring it all together used to mean pages of XML and a lot of ceremony before you wrote a single line of business logic. Spring Boot strips that away with sensible defaults, starter dependencies, and autoconfiguration, so you can go from nothing to a running REST API in minutes, while still dropping down to full Spring configuration whenever you need to.
That's why it remains the default choice for production Java backends across banks, e-commerce platforms, and enterprise systems alike, and why the skills stack cleanly: Spring Core (DI, IoC, AOP) is the foundation everything else sits on, Spring Boot is the opinionated layer that gets you running fast, and Spring Cloud extends it into microservices — gateways, config servers, and circuit breakers — once a single app becomes many. The roadmap below moves through all three in order.
Quick intro — what is Spring Boot?
A quick primer before you start the roadmap. Opens in a small player, no need to leave the page.
The Spring Boot Roadmap
Work through these in order. Each step has a short lesson, official docs, and the tools Spring developers rely on daily.
Spring Fundamentals & Architecture
Why Spring exists, its core terminology, and the layered architecture every Spring application is built on.
Dependency Injection, IoC & AOP
The core idea that makes Spring Spring: the IoC container, dependency injection, bean scopes, and aspect-oriented programming for cross-cutting concerns.
Spring MVC & Annotations
Handle HTTP requests the Spring way: controllers, request mappings, and the annotations (@RestController, @Autowired, and friends) you'll use constantly.
Spring Security
Authentication and authorization the Spring way, plus modern token-based auth with OAuth2 and JWT.
Spring Boot Essentials
Starters that bundle dependencies for you, autoconfiguration that reads your classpath, and actuators that expose health and metrics endpoints out of the box.
Data Persistence: Hibernate & Transactions
Map objects to tables with Hibernate, understand entity relationships and lifecycle, and manage transactions so your data stays consistent.
Spring Data
One consistent repository pattern across data stores: Spring Data JPA for relational databases, Spring Data MongoDB, and Spring Data JDBC.
Microservices with Spring Cloud
Split a monolith into services with confidence: gateways, centralized config, circuit breakers, service discovery with Eureka, and Micrometer for observability.
Servlet Architecture & JSP
The lower-level Servlet layer Spring MVC sits on top of, and how JSP files fit into older or hybrid Spring web applications.
Testing Spring Boot Applications
Slice tests with @SpringBootTest and @MockBean, JPA tests against a real (or embedded) database, and MockMvc for testing controllers without a running server.
GitHub Projects
Real, buildable projects to put on your own GitHub
Build a REST API with Spring Boot
Stand up a CRUD REST API with Spring Web and Spring Data JPA on top of an embedded H2 database.
Secure an API with JWT
Add Spring Security to an existing API, then issue and validate JWTs for stateless authentication.
Build a Microservices Gateway
Split a monolith into two small services, then route traffic between them with Spring Cloud Gateway.
Write a Full Test Suite
Add unit tests with @MockBean, slice tests for the JPA layer, and MockMvc tests for every controller endpoint.
Track complete
Ten steps, from IoC fundamentals to a tested microservices stack. Push what you built to GitHub so it's visible to employers, then keep going — Spring is learned by wiring real beans together, not just reading about them.
Where next?
Keep exploring by domain or drill into a single skill