[gertlex]

I wonder if you've heard the expression "hitting your stride".

(native english speaker who was a bookworm as a kid; I admittedly had to ask gemini to recall the general phrase that I had in mind)

[dgan]

Nope, never heard!

[komali2]

It's similar to "getting into the rhythm of something" (non musical), but is a more permanent implication, you coming from a place of a novice and moving into someone more familiar with e.g. a given job.