There have been some really good, helpful posts on this already:
https://community.intersystems.com/post/robust-error-handling-and-cleanu...
https://community.intersystems.com/post/registering-new-error-code-and-e...
InterSystems IRIS is a Complete Data Platform
InterSystems IRIS gives you everything you need to capture, share, understand, and act upon your organization’s most valuable asset – your data.
As a complete platform, InterSystems IRIS eliminates the need to integrate multiple development technologies. Applications require less code, fewer system resources, and less maintenance.