Interactive display of data sets. Mostly in finance, but I've worked in a few other industries where the same patterns apply. The focus of my development time is building out interactivity and optimizing data loading. Generating pages is the easy part.

As an example, I don't care about bundle size at all. A given app might have a hundred users all on desktop loading from an internal network. I will happily add a few MBs to the bundle if it increases the development velocity of my team.