Example embodiments provide for a system configured to provide constrained delegation and connection pooling for a back-end server by providing a variable identity pipe between it and a front-end server. A client will authenticate to the front-end process using credentials that are typically non-delegable by default, e.g., a token, certificate, or the like. The front-end is configured to extract client identity information and use this information to request changing an identity associated with the variable identity pipe. In addition, requests for actions on resources received from the client can be transformed into remote procedural calls and used by the back-end server to process the requests. A response is then sent back over the variable identity pipe to the client via the front-end server. The variable identity pipe is left open to allow other requests from other clients to be sent over the variable identity pipe in a similar manner.