David Parnas is a prominent computer scientist known for his contributions to software engineering and systems design. He is particularly recognized for his work on modular programming and the concept of information hiding, which emphasizes the importance of separating a program's interface from its implementation. This approach helps improve software maintainability and reduces complexity. Parnas has also been involved in the development of formal methods in software engineering, which are mathematical techniques used to specify and verify software systems. His research has influenced various areas, including software development, programming languages, and system architecture, making him a key figure in the field.