1. A system adapted to provide low-latency computational capacity from a virtual compute fleet, the system comprising: an endpoint management system comprising one or more hardware computing devices adapted to execute specific computer-executable instructions and in communication with a virtual compute system configured to provide low-latency computational capacity, wherein the endpoint management system is configured to at least: receive from a caller a request to access a first resource of a plurality of resources maintained by the endpoint management system, wherein the request contains one or more request parameters and a uniform resource identifier (URI) associated with the first resource, generate a code execution request to execute a program code associated with the first resource, wherein the code execution request contains information identifying the program code and the caller; send the generated code execution request to the virtual compute system to cause the virtual compute system to execute the program code identified by the code execution request; receive a response from the virtual compute system, wherein the response is based on executing the program code associated with the first resource; process the received response based on a pattern matching definition made available to the endpoint management system prior to the receipt of the request to access the first resource, wherein the pattern matching definition comprises a plurality of conditional checks configured to determine whether a corresponding plurality of strings are contained in the received response; and send a return response to the caller based on a result of the processing based on the pattern matching definition.