Programmers Programmers write the code that tells computers what to do. System code tells a computer how to interact with its hardware; applications code tells a computer how to accomplish a specific task, such as word processing or spreadsheet calculating. Systems programmers must be familiar with hardware specifications, design, memory management, and structure, while applications programmers must know standard user interface protocols, data structure, program architecture, and response speed. Most programmers specialize in one of the two areas. At the start of projects, applications programmers meet with the desig