When it comes to collaboration tools in the workplace — Slack, Teams, Mattermost, etc. — I've ranted about this for many years. If you've worked with me professionally, you've probably heard me talk about how much I hate direct messages (DMs) at some point.
Here's why they're bad for you, bad for your team, and bad for your culture.
They hide information
When you DM a teammate about something you need, something they're working on, or anything other than a meme or a personal joke, you're hiding information from others. The whole point of messaging apps at work are to collaborate quickly. Information should be opt-in, but people can't opt-in or manage what they're consuming if you're hiding it in a DM.
When we make information public, we allow anyone who's interested to consume it, but we also allow those who may have context we're missing to jump in. This can be a really important feature, especially when building software in an dynamic environment — which most every business is.
Messaging apps are not email
Stop firing up a private DM between 6 people as if you're sending an email and
CC'ing those you think need to be in the loop. Either find a public channel
that's on the appropriate topic, or create one. Channels are free. Mention
people using their handle (@SoAndSo) and let them decide whether or not to
follow along or contribute. Remember, channels can also be temporary, but they
still create a space to collaborate and the info is there forever if you need
it.
DMs get lost
There's been plenty of times when I've been DM'd about something time-sensitive, read it by accident on my phone, gotten to my desk 15min later and forgotten all about it. If it had been in a public channel, my teammates would have also seen it, and I probably would have been visiting that channel anyway and seen it again.
DMs disappear
At many companies, they enforce a retention policy of 3 months or so for all direct messages. That means if you DM me something important and in 3 months and 1 day I need to remember what we talked about, I can't. It's gone.
When information is in channels, even larger companies have a 5 year retention policy, so you can refer back to it. Beyond that, it much less likely to be useful.
Private channels are also problematic
I'll even say I'm not a fan of private channels. What are you hiding? I've rarely been in a private channel that isn't creating an environment that would be much better off in the public eye. When you create a private channel you're creating an in group and by definition an out group. Human nature is going to take over and things can get toxic if you're not careful.
Being open and transparent can be hard and make you feel uneasy. But, the trade offs are worth it. It will create trust, makes you more approachable, and keeps you honest.
Exceptions to the rule
There are times when a direct private message is appropriate. There's a clear idea about human interaction in groups: praise should be given in public, feedback should be given in private. So, it is ok to share feedback with someone privately. Feedback is a gift, but doing it in public can often make the person on the receiving end uncomfortable.
However, you should also be giving feedback face-to-face so that there's less room for misinterpretation.
One other case is sharing memes. But...why don't you just have a meme channel? What the hell? Share with the rest of the class.
Keep the DMs to an absolute minimum or not at all. Trust me. You'll be better off.