1. A method to provide annotations to a target system to use to execute a code block, the method comprising: examining the code block to be annotated with one or more static annotations and one or more dynamic annotations, wherein the dynamic annotation changes at the target system during execution of the code block; specifying a quality of service level to execute the code block with a reduced energy expenditure, wherein the quality of service level is different from the reduced energy expenditure; while examining the code block to be annotated, determining a hardware customization to support the specified quality of service level; identifying annotations based, at least partially, upon the determined hardware customization and a system software configuration associated with a data block and that specifies how to process the data block when the code block is executed; and providing the identified annotations to the target system to cause the target system to: modify one or more of the identified annotations to vary the determined hardware customization as a function of available energy, available memory, or available storage capacity on the target system to obtain a varied hardware customization associated with the modified one or more annotations, and apply the one or more annotations at the target system during an execution of the code block at the target system using the varied hardware customization associated with the modified one or more annotations.