2026 04 15 CinJUG Meetup

Authentication and authorization require distinct handling in modern software architectures to ensure robust security. Authentication verifies identity, while authorization determines access levels, and conflating these processes often creates unnecessary vulnerabilities. Implementing the Backend for Frontend (BFF) pattern effectively isolates security concerns, keeping sensitive tokens out of client-side applications and significantly reducing the attack surface. Using Spring Security simplifies the integration of OAuth2 and OIDC, allowing developers to manage security contexts and token lifecycles through automated filters and annotations. Token exchange serves as a critical mechanism for limiting claim exposure and enforcing the principle of least privilege across microservices. By centralizing authentication at the edge and delegating fine-grained authorization to specific resource servers, organizations maintain consistent governance while enabling scalable, secure development across diverse business segments.