I would be wary of using any German registrar because of extremely weak privacy laws in the country (impressums etc)
No bs, default WHOIS anonymity, always cheap prices, you can pay in crypto and very very nice support staff
//EDIT: Oh, they’re in the US :( Too bad, disregard
Try domainfactory.de, I used to have one there. Pretty good experience overall
Their website is fast and allows batch queries for when you're trying to find a new project name. Prices are reasonable. I've never used their included hosting or email, though. 3rd party Nameservers like CloudFlare work great.