The New Relic Node.js agent 1.28.0 introduces new visibility into Express app middleware, providing metrics for each middleware function executed in a transaction and displaying the execution time of individual segments within slow transactions. With this release, users can now see which middlewares execute in a given transaction, making it easier to identify performance bottlenecks in their applications. The updated agent also instruments error handling and routes, allowing users to view detailed breakdowns of how errors are handled and where time is being spent in their Express apps. Additionally, the new release provides better support for mounted apps and routers, enabling users to see the path displayed in the Breakdown table and a separate segment representing the router in transaction traces.