software design

The architect without the stonemason is not designing cathedrals, but castles in the air. —Gerald Weinberg
How important are software design skills to a programmer? Programmers, in the traditional, and perhaps most widespread, view of the software development process, are not themselves seen as designers but rather as people who implement the designs of other people. The job of the programmer, after all, is to write code. Code is viewed as a "construction" activity, and everyone knows you have to complete the design before beginning construction. The real design work is performed by specialized software designers. Designers create the designs and hand them off to programmers, who turn them into code according to the designer’s specifications. In this view, then, the programmer only needs enough design skills to understand the designs given to him. The programmer’s main job is to master the tools of her trade.

What about the role of the programmer on a maintenance project, and the resulting importance of programmer-owned design? Most of the time, I think, when developers talk about software development in the abstract and when authors write about development techniques, there is an implicit assumption that everyone is talking about the development of new software. However, many (most?) programmers are not working on the from-scratch development of brand new systems (even though that’s probably everyone’s preference). Instead, they are working on the maintenance of existing production systems, either in a bug fixing mode or in an extension mode, adding new features or otherwise evolving the software in new directions.3