>I was condescended to by some other engineer who though he knew more than me because he was a man
In my experience this isn't "because he was a man" but because he was an engineer. And from what I've seen it also has nothing to do with you being a woman. Engineers tend to be condensing, and will do so indiscriminately. Or said different being "condescended to by some other engineer" means they are treating you equally, if you're not then you are getting preferential treatment.
Perhaps, but I've seen it directed towards numerous female engineers, from less senior engineers who were noticeably deferential to male engineers, at or below the seniority of the female engineer.
I think there's this perception amongst male would-be engineers that starts in college or earlier that women in that space are not sincere enough in their desire to become engineers, are physiologically incapable of doing the work at the same level as men, or that women have entered the space by means unrelated to the mastery of the materials.
I think your comment is a good demonstration why this is still such an issue, despite the overwhelming evidence of gender based discrimination in tech, people are dismissing the experiences of the majority of women in tech. Can't really improve if people are still in denial about it.
I don't know what to do, you can't teach people empathy or not to be sexist. Given how weirdly conservative young people are nowadays I don't see it getting much better in the future either.