That's what I thought. Can employers in Germany actually choose to hire men or women for a position? And under what circumstances is that allowed or common?

The use of f/m or w/m results from the fact, that most of the job titles are gender specific, as are german nouns in general. An example: Programmierer is a male programmer, Programmiererin is a female programmer. So "Programmierer (w/m)" is a shortcut for "Programmierer oder Programmiererin"

Ahh, I see. I also noticed some postings that said “Programmierer(in) (m/w)”, which seemed redundant, so it kind of threw me off the trail. Thanks for the info!