1. A method, performed by an optimizer module that functions as a proxy between a server that provides access to a resource and a number of clients, for optimizing the performance of the server, the method comprising: receiving, at the optimizer module, requests for accessing the resource from a number of clients; buffering the received requests during a buffering interval; creating a number of bulk requests by combining multiple buffered requests into each bulk request; creating mappings which define where to send responses to the requests combined into each bulk request; after the buffering interval, sending the bulk requests to the server, each bulk request comprising a single call to a web services application programming interface (API) that specifies each of the multiple requests that have been combined into the bulk request; for each bulk request, receiving a bulk response that includes multiple responses corresponding to the multiple requests; parsing each bulk response to extract the multiple responses; employing the mappings to identify the corresponding client for each of the extracted responses; and sending each of the responses to the corresponding client based on the mappings.