router.param is a powerful tool that we can use to keep our code from repeating core functionality through routes. This is a pattern we want to frequently follow: identify multiple pieces of code that accomplish the same goal, put it into a single component, let that component do that thing (and update it when we want the thing it does to change — in a single place).

Let’s try applying that knowledge again, to another codebase. If you look at the workspace you’ll find the same problem of data-lookup happening, based on a URL parameter, multiple times in different places. Try combining that logic in a single place using router.param.