If you're moving to Germany, Austria or Switzerland for work, the useful question isn't how good your German needs to be. It's which German you need first — because the language of your workplace and the language of your daily life may be entirely different problems.
Your job may be in English
A great many professional roles in German-speaking countries, particularly in technology, research, engineering and multinationals, operate in English. People arrive expecting to need German for work and find they don't.
What they do need it for is everything else: the Bürgeramt, the lease, the doctor, the school, the neighbour, the tradesman, the letter from an authority that arrives in dense bureaucratic German and matters.
That's the part nobody prepares for, and it's where the frustration lives.
What to learn first
Bureaucratic reading, more than you'd think. Official letters are formal, nominalised and unforgiving, and they carry deadlines. Being able to work out what a letter from an authority is asking for is worth more in your first six months than conversational polish.
Appointments and services. Booking, rescheduling, explaining a problem, asking what a document means. Transactional German, repeated constantly.
Numbers, dates and addresses, cold. On the phone, at speed. This sounds trivial and is where people fail in practice.
Your own situation. Your job, your family, why you're there, what you need. You'll say it dozens of times in the first month.
The level that actually changes things
A1 lets you be polite. A2 lets you survive transactions. B1 is roughly where life stops being hard — you can handle an unexpected conversation, follow most of what's said to you, and deal with an official exchange without preparing it.
B1 also matters administratively in several contexts, including some residence and citizenship processes. Check what applies to your own situation and country, because the requirements differ and change.
Start before you go
The first three months after a move are the worst time to begin. You'll be exhausted, overloaded with admin, and every interaction will be high-stakes.
Arriving with even A2 changes that experience substantially — not because A2 is much German, but because it's the difference between participating badly and not participating.
The trap once you arrive
English works, in cities especially. Colleagues switch to it, service staff switch to it, and switching is kind.
Which means immersion doesn't happen automatically. People live in Berlin for five years at A2 because every difficult conversation got conducted in English the moment they hesitated. If you want the language, you have to decline the switch — and that's a decision rather than a learning problem.
What to arrange in advance
Regular speaking practice with a teacher, starting before the move and continuing through it. The move is exactly when self-study collapses, and a scheduled hour is what survives a chaotic month.