Technical communicators are often involved in the design of interfaces and technical systems. This is because we always have a strong user focus. In order for technology to do the job we want it to do, it must be designed in a way that supports the user in accomplishing their tasks. We also call this task-based development, as opposed to the feature-based development that we often see.
Task-based development, and consequently, task-based documentation — user guides written from the perspective of how to use the technology to accomplish one’s tasks — puts the focus on the needs of the user. Instead of just cool technology, we have technology that meets user needs and does what the user needs it to do.