Another service I want to give some credit to is Azure AD DS. This service builds a bridge to services that depend on AD DS or Lightweight Directory Access Protocol (LDAP) and Azure AD. Azure AD DS is an AD Lightweight Directory Services (LDS)deployed over Azure AD. It allows read access through common AD DS calls and can handle normal domain identity and access. In the majority of use cases, Azure AD DS can replace a classic AD DS.
For the deployment and more, consult the documentation for this service: https://docs.microsoft.com/en-us/azure/active-directory-domain-services/active-directory-ds-overview.