How do you guys collaborate on your own projects (at work, private, whatever)

[aliak]

It seems to be a mix of a number of tools that are used, e.g. 
jira, github, trello, google docs, slack, etc. And which ones are 
preferred depends on if you're a product manager, designer, or 
developer.

TL;DR: I'm curious to know what works for people here. Which 
tools do you use for projects, where are the pain points, and 
what are features that are missing?

For the D developers especially, what are the pain points of 
managing a project such as dlang? What are the tools that are 
useful? Why are they useful? Which tools have failed you? What's 
missing?

I ask because a few colleagues and I have been trying to figure 
out why it's always so hard to make everyone in a software 
project happy with how collaboration takes places, and keep 
everyone on the same page. There always seems to be a problem. 
E.g. Jira is too complicated, everything goes stale in 
confluence, trello doesn't integrate with github intuitively, 
github projects is lacking, no one contributes to the google doc, 
why can't we all just use github issues, slack is too 
synchronous, what you've been working on that too?, who's working 
on feature X?, why did we implement feature Y?, etc.

We kinda have a hypothesis that a document-centric (i.e. google 
doc like place where designs, features, specs are laid out), 
externally integrated tool is the way to go - given that, 
issues/tasks can be created from within the document and the 
integrations can handle broadcasting those issues to whatever 
tools developers/designers are using, while also updating the 
related documents with events that occur.

This would mean that you could have a google doc, write up stuff, 
comment in it, and then create tasks out of the text in the doc, 
which would be synced with say github (i.e. an issue would be 
created in github), and then the resulting commit that fixes that 
issue would bubble back up to the doc and be visually resolved. 
This would keep the document "alive" and would not force people 
to use tools they didn't want to (given the tool they want to use 
provides an API that can be integrated with).

I'd be interested to hear thoughts around this subject.

Cheers,
- Ali