How to build in public?

I have been building my main SAAS project (alongside my full-time job) for about 6 months now (we plan on releasing the MVP this month), additionally whilst working on this I launched a small print on demand e-commerce shop on the side (which made me realise that you can't just share a link on Facebook and then kick back refreshing your stripe dashboard)

And after getting inspired by an article here I decided to give building in public a try.

Admittedly a part of it is for some kind of recognition. Part of it is to share the pain and expertise that has been acquired by going through the whole process of building, finding investors, marketing etc. But mostly I just really want to share my thoughts and ideas in a meaningful way and ideally build some kind of a following (whatever that entails).

Now the first question is - where do you post your updates?

Indiehackers seems a bit too obscure.
On Twitter, I have a whopping 1 follower (who I think followed me with the intention that I would follow back)
Facebook or Linked-in doesn't really seem like the best places to post this kind of stuff
Medium seems a bit too "un-timeliney" to me

Secondly, where do you write your articles? Do you even write articles or only small updates?

The idea in my head is to structure my whole SAAS experience in different categories (i.e. Concept and research, development, marketing, funding, etc) but would Medium be best for this kind of format? Or would creating a small Ghost blog be better?

And all of this also takes time from actually building the products - is it really worth the effort?

tl;dr - "Building in public - How and Why?"

Thanks