Disclosed are various approaches for workflow service back end integration. In some examples, a service request is identified. The service request is associated with a network service. A single sign-on (SSO) token is received. The SSO token represents a user account authenticated with an identity manager. Authentication data for the network service is identified based on the SSO token. A hosting location of a connector for the network service is identified based on the authentication data. An authentication header is appended to the service request. The service request with the authentication header is transmitted to the connector.