Small errors become large when repeated at scale.

An error that is trivial once becomes a structure when repeated. A rounding choice, a slightly wrong assumption, a small courtesy skipped, each harmless in isolation, will produce a large and consistent distortion across a thousand instances. Scale does not just multiply the mistake, it makes it systematic, and systematic errors are the ones that hide because they look like normal behaviour.

Wherever something you do repeats often, it deserves attention out of proportion to any single instance. Look at your defaults, the template, the standard reply, the assumption baked into a recurring process. Fixing one of those is worth more than a great deal of careful work on things that happen once.