effect-v4-observability

To implement observability without coupling domain logic, keep pure-tier libraries free of OTel dependencies and compose telemetry at the application edge using Effect.fn to instrument public fallible boundaries.

Standardize structured logging and metrics in Effect v4 by applying consistent span naming, fiber-aware logging, and the updated Effect v4 Metric surface to track domain-agnostic library operations.

Instrument public fallible boundaries in Effect by using Effect.fn to wrap operations with named spans, ensuring consistent telemetry composition at the infrastructure level without modifying pure domain logic.

No, this observability approach enforces a strict separation by keeping domain-agnostic libraries free of OTel dependencies, allowing apps to integrate OpenTelemetry at the application edge instead.

Fiber-aware logging is required for consistent observability in Effect v4 to accurately trace concurrent operations, ensuring structured logs maintain proper context across asynchronous fibers.

Apply telemetry composition at the application edge when instrumenting public service boundaries, ensuring domain logic remains pure while the app handles span naming, logging, and OpenTelemetry integration.