Optimizely comes with a logging API, which is an abstraction for writing log messages from the system. Logging is useful when you troubleshoot and locate application problems.

Optimizely Commerce Connect uses EPiServer.Logging, which works as a façade for the logging framework in .NET Core (Microsoft.Extensions.Logging). To manage the configuration and output of the logger, refer to the API of the implementing framework, see Logging in .NET Core.

The recommendation for custom logging in Optimizely is to use the logging API defined in .NET Core.