What is required for automatic backend correlation to work given that the EUM agent has...

To successfully achieve automatic correlation between frontend and backend traces, Instana requires backend services to expose a trace identity. The IBM Instana EUM and tracing correlation section confirms: "Automatic backend correlation requires exposure and propagation of the backend trace ID to connect user interaction traces with backend processing traces." When the EUM agent operates in browsers or mobile interfaces, it injects headers containing Trace and Span IDs into subsequent backend HTTP requests. Backend instrumentation must read and propagate these identifiers through service calls so Instana can unify them into a single end-to-end transaction trace. Proper correlation connects a user's session-to-service journey across web, application, and infrastructure layers, a fundamental aspect of Instana’s distributed tracing model. Lacking backend trace ID propagation causes separated traces that cannot be linked, even if HTTPS, SDK, or application perspectives are configured correctly. This mechanism remains fully verified in the IBM Instana Observability Tracing Integration Guide.