AFAIK I know Active Directory has no native support for adding hooks to specific events.
Azure AD on the other hand supports "app(lication) provisioning"" using SCIM.
When your application supports SCIM, or you've built a SCIM gateway to connect to your legacy application, you can use the Azure AD Provisioning agent to directly connect with your application and automate provisioning and deprovisioning. If you have legacy applications that don't support SCIM and rely on an LDAP user store or a SQL database, Azure AD can support those as well.
Most organisations seem to introduce "Identity Management" (IdM) aka "Identity & Access Managent" (IAM) solutions to solve the problem of creating and managing identities, accounts (and often roles and passwords) in a large ecosystem of applications and services that are not AD integrated.
There you would integrate workflows for joining, leaving, transfers, but also the requesting, approving and assigning of roles (and frequently password recovery and password changing) with the provisioning and de-provisioning of those in a myriad of different systems.
In other words: you don't create an account in AD and use that to trigger the creation of an account with the same login in a different system. You add a joiner in the IdM/AIM system and that system has a plugin for AD to create an account there and a second plugin will create an account in another related system.