I’m not recommending this, but when I socially transitioned, I changed my name and came out in every sphere of my life at once. It made it simple, there was no hiding or being one person in one context and being another person in another context - I was “me” in every context.

After 8ish months of HRT I started to pass well enough that some colleagues I hadn’t worked with closely for a few years didn’t recognize me, and when possible I just never mentioned I was trans or who I was before. If someone recognized me, there’s no way to not be honest about transitioning, it was obvious.

Sometimes it was hard to be as honest as I wanted to be, but outing myself with some people felt like a bigger cost than just treating it like a new relationship, but that’s all contextual.

So your experiences may vary significantly depending on how you announce your transition, who you tell, who you don’t tell, when/if you start passing, etc.

I would say it’s important to share with people you depend on as a professional contact - if that relationship is important, sharing you are transitioning makes it easier to keep that relationship going. Particularly thinking of references you would put on a job application, you would ideally let them know who you are well before you transition so they aren’t distracted or shocked by it when you need them.

For people that don’t need to know, there’s no need to disclose. I made all my name changes in a relatively short period of time, and early in transition people tend to want to be polite and are somewhat understanding about it, in my experience (this will vary significantly).

At work I actually announced my transition in a private work chat with most of the people I’ve worked with. Some people ask their managers to share the news, but I’ve always preferred to just communicate directly with my colleagues. (read: I hate and distrust management)

It was later in my transition that I ran into some difficulties, mostly with people not believing I was my deadname - but that eventually got sorted one way or another, it just wasn’t as easy to update things when they don’t see or hear someone who is obviously trans (somehow that was more unnerving for cis people, that they couldn’t tell - there is a sense of explanation and trust when you’re obviously trans, it makes it clear you aren’t lying about who you are / were, whereas when they can’t tell you’re trans, they also can’t trust that you’re telling the truth about who you are / were as easily).