Customer-facing performance gets budget and attention because it is tied to revenue directly. Internal tools rarely get the same scrutiny, even though staff spend more hours inside them than any customer spends on the marketing site.
A dashboard that takes four seconds to load a table trains staff to stop checking it in real time, which means decisions get made on stale numbers — a slower, quieter failure mode than an outage, and harder to notice until it has already cost money.
We hold internal tools to the same performance budget as public pages: indexed queries, paginated tables, optimistic UI on every action. Nobody is going to write a review about a fast internal system, but everybody feels a slow one.