As platforms scale, maintaining secure service authentication across microservices and external APIs becomes increasingly complex. Common issues include misuse of frontend tokens by backend services, scattered API keys, and the lack of a standardized approach to service-to-service authentication. In this talk, Janus demonstrates how Keycloak’s token exchange offers a streamlined and secure solution to these challenges. By enabling service-to-service authentication without exposing user tokens, allowing dynamic API access without managing static credentials, and supporting fine-grained token permissions, Keycloak helps teams enforce least-privilege access while simplifying operations. Attendees will gain practical insights into how to implement token exchange, supported by real-world API examples and recommended best practices. The session is ideal for platform engineers and architects looking to improve the security posture of their service communication at scale.