A software developer is a person concerned with facets of the software development process, including the research, design, programming, and testing of computer software. Other job titles which are often used with similar meanings are programmer, software analyst, and software engineer. According to developer Eric Sink, the differences between system design, software development, and programming are more apparent. Already in the current market place there can be found a segregation between programmers and developers,[dubious – discuss] being that one who implements is not the same as the one who designs the class structure or hierarchy. Even more so that developers become systems architects, those who design the multi-leveled architecture or component interactions of a large software system. (see also Debate over who is a software engineer)