As much as some folks might disagree, there is a difference between just developing software and developing software that will be used by other software developers to create new and interesting products. This includes the people who write business tier and data access tier functionality in an n-tier architecture.

I get in arguments about this kind of thing with folks. They believe I’m expecting perfection, which is something impossible to provide. That’s incorrect; I expect excellence. Understanding the difference between excellence and perfection is important, just as it is important to understand what it is to write code and what it is to write code for people who will use it to write code.

What’s the difference? While I could (and generally do) argue that there shouldn’t be any difference, here’s what I’ve found:

People who write software do error checking. People who write software for people who right software will not only provide meaningful error messages as a result of that error checking but will also add trace and debug statements so someone using it can figure out where precisely the error is happening and how to fix it.

People who write software have documentation. People who write software for people who write software provide API documentation, task-based documentation (HOWTO), examples, remarks, and helpful tips. An undocumented API is almost as useful as a nonexistant API.

People who write software only look at taxonomy and naming in relation to the application. People who write software for people who write software use clear, concise naming for identifiers and filenames that makes sense to people outside the scope of the application and makes use of the API intuitive; and they organize code in structures (namespaces, files, etc.) that make sense beyond just an individual application.

People who write software focus on what needs to be done now. People who write software for people who write software also focus on what will be done in the future. (Which is another way of saying: People who write software extend code. People who write software for people for people who write software make extensible code.)

In short:

People who write software make code that works. People who write software for people who write software make code that is usable.