Support serialization configuration

**Feature request**
It would be great to have monitoring for middleware.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_monitoring` with default `false`.

Start by locating the configuration handling and middleware-related entry points in the repository; the issue does not name specific files or tests. Determine how monitoring should work in production, then verify that the new enable_monitoring option defaults to false and that its behavior is covered before considering the work done.

Written by the indexing model from the issue text.