Need Architectural Style/Pattern For Providing Pre/Post Hooks To Common Tasks In ERP

I am preparing an architecture for a Financial ERP, especially GL, Account Receivables etc. on ASP.Net MVC 5. I need to inject some extensibility points so that external systems can be integrated easily in future. These extensibility points can be stored procedures, scripts, performance counters, external logging and many more. You can consider this scenario as writing extension points or custom routines to Dynamics AX or Oracle EBS.

I know about ASP.Net filters but I don't foresee it a flexible way to provide extension points to external users. It requires modifications in code and break the Open For Extension/Close For Modification principal.

I would appreciate if someone points me to some good and relevant articles or give some suggestions.

Thanks in advance.