When I came out, I worked at a medium size company, kind of late stage startup-ish. I was shocked how accepting it was. The only transphobia I encountered was unfortunately from the head of HR, who made changing my name in the system really difficult. Everyone on my team was really good about my name and pronouns and it wasn't a big deal. Outside the team, some people misgendered me but I didn't really care enough to correct them since I didn't have to work closely with them.

Now I work for a consultancy that has a reputation for promoting diversity, and it's been really great. I'm transfem nonbinary but present very feminine, and my coworkers mostly treat me like a woman which is what I want, when I do get misgendered at work it's usually she/her which is fun since I'm used to people assuming he/him. There are also many other out trans and queer people in the company which is great. Lots of my cis coworkers put their pronouns in their zoom names, email signatures, etc...

There are lots of accepting tech companies out there, just have to avoid tech-bro culture like early startups, and avoid giant enterprise companies where everyone is over 50