Why it matters
The choices under the hood outlast the launch. Viewport affects how reliable a site is to run, how easily it grows and how cheaply it changes when the business does. Getting it right keeps a project healthy long after the first version ships.
In practice
In practice we keep Viewport pragmatic: the simplest approach that meets the need, documented so the next person can pick it up. We favour proven patterns over novelty, and we make sure the result is testable and maintainable rather than clever for its own sake.