Is there a website where people around the world can discuss research during writing? Authors and readers can discuss about the writing of authors including ideas, experience design, hypothesis etc., like what people discuss at stackoverflow, rather than authors only get feedbacks until publishing the paper after all work done.

I am wondering if there is any website for researchers around the world to discuss about their research.  (Thanks for Buffy.)

I know researchgate but it seems not for the purpose. 

Thank you.
In the 20th century newsgroups like, e.g., 

https://groups.google.com/forum/#!forum/sci.physics

were perfect for this, they still exist and you can narrow down the scope and audience of such a group by creating one on your own. Nowadays probably more scientists in such a field post and read on bulletin boards like

https://www.physicsforums.com/

or 

https://physics.stackexchange.com.

But, professional scientists don't have much time for long discussions. I think this is also the reason the Q&amp;A format attracts much more then bulletin boards or formerly newsgroups. Academia is about asking the right questions, if you have the question, you have to work on it based on scientific rigor and methodology. There is not so much to discuss publicly before or during doing this work or writing papers and hypothesis. Science is about coming up with a way to solve or answer a question and comparing/commenting on that. The aftermath, discussions come afterwards, when work and answers have been published. So my experience is with disccusion formats you attract in best case undergraduates and early PhD students still learning. Professional scientists mostly have private or public discussions on conferences. 

So the best option you might have to discuss with experts on your topics online are virtual conferences where maybe a chat or comment app is attached to each talk. I'm wondering myself how easy and cheap web-technology has become here as I'm now registered for a big conference in my field which will not be canceled with respect to corona virus due to organization cost but many presentations will be shown online after remote registration.

Researchgate I think also can work for this if you have enough followers reading your posted questions. Online, the question is always how do you advertise your post to readers and commenters you are looking for.