Backend with Spring Boot 4
An 8-step path through a real backend — from the first line to auth, deployment, and Spring MVC failure contracts.
- Difficulty
- Intermediate
- Lessons
- 8
Java 21 + Spring Boot 4 powers most production Korean backends — strong types, mature ecosystem, proven patterns.
By the end:
- Understand multi-module Spring projects
- Treat SQL as SSOT, JPA/MyBatis as readers
- Design REST APIs to spec
- Add JWT authentication
- Write integration tests with
@SpringBootTest+ Testcontainers - Deploy with Docker + Caddy
- Design Spring MVC request, error, and timeout boundaries as a stable API contract
Flow
From backend basics to operability
Define backend responsibilities and run the first application.
Treat SQL as the data contract and design REST inputs, outputs, and failures.
Implement the JWT boundary and freeze contracts with automated tests.
Verify an operational deployment and separate MVC responsibilities clearly.
Steps 1–4 are how to build it. Steps 5–8 are how to keep it safe, stable, and explicit about failure.
Prerequisite — getting-started + Java 21 installed.