Case study
Backend security / Open source
Spring Boot Secure API
A production-grade REST API template that makes authentication, hardening, observability, and testability part of the foundation.
- Role
- Creator · Backend architecture
- Year
- 2026
- State
- Open-source template
System / clustered
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Project snapshot
The condition
Challenge
Most API tutorials stop before the operational concerns a production service needs: token lifecycle, abuse controls, auditability, observability, and architectural enforcement.
The response
Architecture
A Spring Boot 3.4 reference service layers correlation, rate limiting, JWT verification, authorization, audited application logic, and PostgreSQL persistence into one documented request path.
What shaped it
Key decisions
Rotating token families
RS256 access tokens are paired with refresh-token rotation and family revocation to detect reuse.
Security in the request path
Argon2id, account lockout, Bucket4j limits, OWASP headers, and explicit authorization rules are first-class layers.
Operational evidence
Micrometer metrics, JSON logs, audit records, Testcontainers, ArchUnit, PIT, and JaCoCo make behavior observable and testable.
How it feels
Experience
The reference exposes registration, login, refresh, health, and Prometheus endpoints. OpenAPI can be enabled per environment, while structured errors and correlation IDs keep requests traceable.
What resolved
Outcome
A public MIT template backed by more than 70 unit and integration tests, architecture rules, mutation testing, coverage reporting, and automated CI checks.
- 70+ automated tests
- CI quality gates
System composition
Technology, deliberately chosen.
- Java 21
- Spring Boot 3.4
- PostgreSQL 16
- Gradle
- JWT RS256
- Prometheus