From experience: after company grew to more than .. 200-300 people and user management/termination became a big burden we hired a person that would write tools to automate user management, and if something wasn't supporting SAML we did manage users via its API. If API was not available then we reverted to "Termination checklist" aka manual work.
Clarification: it wasn't that persons only responsibility, just one of many assignments to help automate Ops in the company.
Clarification: it wasn't that persons only responsibility, just one of many assignments to help automate Ops in the company.