Intransitive verb used with に for the person, thing, level, or pace one catches up to. It can be physical or abstract, and is often negative as 追いつかない, meaning something cannot keep up.
There are too many orders, and production cannot keep up.
2
godan verb (-ku), intransitive verb
be made up for; be compensated for; make up for one's losses
Limited use for a loss, mistake, or damage being made good; it is especially natural in negative expressions such as 追いつかない, meaning that compensation or regret is no longer enough.