I guess I was pretty lucky to get a job at where I work now.. At the interview, I told them my prefered pronouns, the name I would be changing to legally, and that I would be starting hormones.. I am lucky to live and work in a very diverse and queer friendly area with managers that may not *get* it, but have been exposed to trans people and were cool with taking me for who I was and on my work history and not my gender..
Not everyone is that lucky or CAN be that open with an employer. If I were still living in the South, I doubt very much if I could have gotten the job I have now and transitioned while working.. Thankfully, I was and am that lucky.. The customers have seen me transition and have asked questions, some are just confused and think they pegged me as female by mistake. I get to educate others on transgender issues and I have tried to invite a more open and welcoming attitude to those along the gender spectrum..
This is just my experience, like I said, I kinda lucked out in some ways. I would never suggest that anyone put themselves in danger by transtioning on the job, but it can work out. Just my .2 on the subject
-Tony