As a very general rule, Germans tend to address each other formally at work unless they explicitly agree to be on more familiar terms with one another. Especially in the older generations, it is not unusual for colleagues who have known each other for many years to continue using “Sie” and to address each other as “Herr X” and “Frau Y”.
In younger generations, especially among professionals who have spent some time in English speaking or Scandinavian countries or work with professionals from those countries on a regular basis, there is a growing tendency to drop the more formal “Sie” and to use “du” and first names.
When you are talking to your boss or supervisor, you should start by addressing him or her formally by using “Sie”. If you know that your boss or supervisor has a title such as a PhD you should call him or her Dr. X / Dr. Y instead of “Herr X/Frau Y”. In general, German companies tend to become less hierarchical than they used to be in the past. If you’re working for a startup, it is highly unlikely that even the CEO will want to be addressed as “Sie”.
To be on the safe side and especially if it is a more traditional company and you are new to it: start by using “Sie”. If you are too formal, your colleagues will soon let you know by introducing themselves with their first name and offering you to use the informal “du”.
At training events or trade fairs where you meet knew people, you should always use “Sie” unless it is a Geek or tech event where everybody is below 30.