Welcome to the coda forums!
What do you want to do with the functionality? is it just to do Instant messaging? The downside of something like slack, is it just speeds up your existing tools, leading to even greater overload, and a constant pinging.
One of the biggest problems in my existing project is an overload of email messages - I have 1500 unread mails from just the last 2 months.
From my perspective I am trying to reduce the need for communication by finding a way to bring topics to the fore, and having a central discussion place for them. None of these are easy - not so much because the technology is difficult, but because the people… and the company policies…
For specific issue resolution:
What I am currently doing at the office is that I have an “Issue Driver List” in Excel. IT IS NOT AN ISSUE LIST. The idea is that things that needs to be discussed with specific teams be recorded here, with the next step, and the person responsible for doing the next step. Once the issue has been resolved, the Final Answer is recorded, and saved for future reference. But I just had a case of somebody adding 4 emails to my existing 1000+, over the period of a month - needless to say, I never saw those. If it had been recorded in the driver list. I would have picked it up and answered. It was a simple question about whether a field should 100 or 1000…
I have also built a version in coda, which would work much better than Excel. It could also morph into a fully fledged requirements gathering tool.
The doc is here
A video explaining is here.
A video showing reporting is here
This is very much a tinker doc, to play around - turns out the company is not interested AT ALL. But one could also link it to e.g. Zoom to schedule discussions. Optionally via Google Calendar.
Another alternative would be a community building tool like Tribe. This will allow you to set up groups of people, and provide topics, around which discussions can take place. I have built a Coda Education Community here.
This is still very new - I have created Groups for beginners, medium level and advanced coda users. Posters can judge their topics, and decide which group to post in. People looking to learn, can then go to a specific Group based on their own experience level.
Posts can also be assigned a Topic. In this example I have created (so far) Collective Topics for buttons, formulas and tables.
But as I said up front, it depends what you want to achieve. It could be that after looking, you decide that Whatsapp is still the best.