[erroneousfunk]

Right, and I have "girls' night out" with my friends and occasionally address them as "hey girl!", but god help the new co-worker who comes up to me and says "you're a girl software engineer!"

Honestly, I can't believe you'd think that would be remotely appropriate in this context (or that I'd even have to have this discussion on Hacker News at all, or that ainiriand would feel a sense of "pride" as a male -- yeah, I checked his gender -- over a group of female biologists -- a science that is more than 50% female...)

"Guys" is casual. "Guys" is sometimes used for a mix-gendered group, but with a female-only group, you might use "Gals" or even "Ladies," but "Girls" is only used if you want to emphasize youth/casualness/fun (hence, the group of 50-something's calling themselves "the girls")

I've lived on the east coast, I've lived on the west coast, I've spent a great deal of time in the middle -- no one refers to a group of women in a professional context as "girls." After mid-puberty, that word starts to carry specific connotations when used as a description.

[biot]

I'm not saying it's appropriate; just offering a possible explanation for the use of the word. Personally, I'd just go with "female" or simply saying "she's a software engineer" gets the point across well without having to delve into sex vs. gender identity etc.

[erroneousfunk]

You certainly seemed ready to defend lev_k. Someone makes a ridiculous comment like "Maybe 'scientists who are girls' would be more befitting?" (I thought that was hilarious until I realized they weren't joking) mcv calls him out, and then you jump in and explain why "girls" is okay to use here?

Again, it's not. It's really really not. Outside of pop song lyrics and college parties "girl" is not the opposite of "guy." And if you don't understand the connotations/subtle unspoken irony when a middle aged woman says "she's going out with The Girls" (and, yeah, my white-haired grandmother still says this -- she's less serious and more vocal about the phrase every year) you probably shouldn't be using the word at all when you're referring to anyone over the age of 12.

So, okay, great, you said you wouldn't actually use it. But why were you defending it, or... trying to come up with an explanation and using your 50 year old female friend as a rationalization? I don't get it.

[biot]

You're making many false assumptions about my motivations, then proceeding to tear them down. As I'm not really interested in debating strawwomen, I wish you the best.