Here some random thoughts / observations:
Hiring women because "we need at least one woman on the team because of the quota". Would you like to know you have been hired because the team is forced to have a women and everybody knows it?
Same company. I have received an email that you can "get bonus if you refer a friend that gets hired." Then a list of how much you can get depending on position. Then a note -- "if a woman, the reward is tripled".
Promoting women before they got enough experience. Similar to above. You have been put on a fast track for promotion but you haven't had time to get the needed experience. Everybody knows this (and discuss behind your back) but nobody is going to tell it to you. Now you have two problems.
On topic of feedback, people need feedback to improve, but female developers will not get it. All-positive feedback is no feedback at all because you are nowhere closer to knowing what you are doing wrong. I have personally been doing some pretty stupid things (like taking credit for other people work) until somebody told me and I fixed it. I wonder what would I do if nobody dared to tell I am doing anything wrong, or if my salary or position in the team had nothing to do with how well I am actually doing?
Just because guys can't be hitting on girls in the office doesn't mean it isn't there, but now it is more comical.
Just because people aren't supposed to discriminate women doesn't mean it is not there. Male developers seem to be in large part focused on the fact the words are spoken by a female rather than their merit. I have seen concrete examples. It kinda seems it is still true you need to (at least in some cases) work twice as hard to prove anything, but now male employees got better at hiding their discrimination. I am half decided that maybe all the focus on discrimination achieved is push the discrimination underground.
Discussions quieting down when you show up. Or tame behavior when eating lunch. Guys reminding other guys that a woman is present. Supposedly because it is not proper to behave like that (but it is fine when only guys present?) Imagine this happening every time.