Systems, methods, and computer-readable media are provided for reusing execution environments and code of serverless functions while ensuring isolation in serverless computing environments. In some examples, a method can include, in response to a first request to run a serverless function, executing, at an execution environment on a network, computer-readable code configured to perform the serverless function; after the computer-readable code has executed, modifying a pointer to an area of memory used to store a first state of the serverless function to reference a different area of memory; in response to a second request to run the serverless function, reusing, at the execution environment, the computer-readable code to perform the serverless function; and based on the pointer referencing the different area of memory, using the different area of memory to store a second state of the serverless function.