I founded a UG and a GmbH in 2024. It took me 3 months total including visits to the notary (who charges a non-insignificant sum for their services).

I did this as a subsidiary for a US company and literally had to email and call people every few days to move the process along (mostly, it was the banks who somehow expected us to be a multi-national company and wanted to charge an arm and a leg just to let us open a bank account. Most banks outright refused us).

When the notary finally filed the paperwork to the court, the court replied after a few weeks with additional clarifications for which we had to go AGAIN to the notary to do the whole song and dance of them chanting at us in German at 1000 words per minute.

Everything took painfully long and delayed investment for while. People have absolutely no idea how painful it is to merely have the incorporated entity available. Then, it takes a few weeks to get your tax ID - this is when you can start employing people / accepting payments etc.