A common policy I've seen from engineering managers who code (and one I've stuck to myself when I've been in engineering management roles) is to avoid writing code that's on the critical path to shipping.

That's means your team should never be blocked on code that you are responsible for, because as an engineering manager you can rarely commit dedicated coding time to unblocking them.

This still leaves space for quite a few categories of coding:

- prototypes and proof of concepts

- internal "nice to have" tools that increase developer quality of life (I ended up hacking on plenty of these)

- helping debug issues