When refactoring an existing product, don't try to make it perfect.

A successful product tends to grow organically in very messy ways that accumulate debt.

It's hard to pay down that debt continuously, so it often accumulates into a big pile until something simply must be done.

In that project to fix it, it's tempting to figure out the perfect, decade-durable version and implement that--who knows when you'll get to tweak it again.

But that machined perfection is extremely hard to retrofit onto a messy, living thing (especially one that's not staying still!)

It's easy to get into a trap of going into a cave to try to get the plans perfect.

It's much better to do small, almost-certainly-a-good-idea improvements continuously.