[013a]

Its especially strange when you think about how unoriginal Slack's product domain is, and how comparable, and in some cases small, their userbase is.

* iMessage, which likely handles something in the range of 750M-1B monthly actives.

* WhatsApp, 2B users [1], though no clarity on "active" users.

* Telegram, 400M monthly actives [2]

* Discord, 100M monthly actives [3]

* Slack, 12M daily actives [4]

* Teams, which is certainly more popular than Slack, but I shudder to list it because its stability may actually be worse.

The old piece of wisdom that "real-time chat is hard" is something I've always taken at face-value as being true, because it is hard, but some of the most stable, highest scale services I've ever interfaced with are chat services. iMessage NEVER goes down. I have to conclude that Slack's unacceptable instability, even relative to more static services like Jira, is less the product of the difficulty of their product domain, and moreso something far deeper and more unfixable.

I would not assume that this will improve after they are fully integrated with Salesforce. If your company is on Slack, its time to investigate an alternative, and I'm fearful of the fact that there are very few strong ones in the enterprise world.

[1] https://blog.whatsapp.com/two-billion-users-connecting-the-w...

[2] https://techcrunch.com/2020/04/24/telegram-hits-400-million-...

[3] https://wersm.com/discord-reaches-100m-monthly-active-users-...

[4] https://www.cnbc.com/2019/10/10/slack-says-it-crossed-12-mil... (this was also announced on Slack's blog, but that's down).

[jjice]

I didn't realize that Discord has way more active users than Slack. I'm glad, Discord is a fantastic service in my experience. It's a shame they got shoe horned into a mostly gaming oriented service. I've never had a class or worked somewhere where Discord was a considered solution instead of Slack, but I can't think of anything that Slack does better (in my experience). In general, I think Discord has the best audio and video service that I've used, especially kicking Zoom to the curb.

[013a]

Discord is definitely in the same realm of scale as Slack, and probably bigger (they publish different metrics, so its hard to say for sure).

The really impressive thing about Discord's scale is the size of their subscriber pools in the pub-sub model. Discord is slightly different than Slack in the sense that every User on a Server receives every message from every Channel; you don't opt-in to Channels as in Slack, and you can't opt-out (though some channels can be restricted to only certain roles within the Server, this is the minority of Channels).

Some of the largest Discord servers have over 1 million ONLINE users actively receiving messages; this is mostly the official servers for major games, like Fortnite, Minecraft, and League of Legends.

In other words, while the MAU/DAU counts may be within the same order of magnitude, Discord's DAUs are more centralized into larger servers, and also tend to be members of more servers than an average Slack DAU. Its a far harder problem.

The chat rooms are oftentimes unusable, but most of these users only lurk. Nonetheless, think about that scale for a second; when a user sends a message, it is delivered (very quickly!) to a million people. That's insane. Then combine that with insanely good, low latency audio, and best-in-class stability; Discord is a very impressive product, possibly one of the most impressive, and does not get nearly enough credit for what they've accomplished.

For comparison; a "Team" in Microsoft Teams (roughly equivalent to a Discord Server or Slack Workspace) is still limited to 5,000 people.

[pr0zac]

I really agree Discord is amazing and wish I could use it for work instead of Slack.

I think the big things that prevent it from being adopted more for professional use is the lack of a threading model (even though I hate it when people use threads in Slack) and the whole everyone in every channel except for role-based privacy settings. The second one especially is a big deal because you can't do things like team-only channels without a prohibitive amount of overhead.

That said (with zero knowledge of their architecture) I have to feel like both of those missing features aren't too terribly hard to build. Its very likely Discord is growing as a business fast enough on the gaming and community spaces they don't feel the added overhead of expanding into enterprise (read: support, SLAs, SOC, etc) makes sense and are waiting until they need a boost to play that card.

[joshstrange]

> I think the big things that prevent it from being adopted more for professional use is the lack of a threading model

They do have a threading model now (if you are talking about replying to a message in a channel and having your reply clearly show what you are responding to). If you are talking about 1-on-1 chats with other people in your same server then yes, that is still lacking IMHO in discord. The whole "you have to be friends" to start a chat (or maybe that's just for a on-the-fly group) is annoying.

[013a]

Discord gives every user an identity that is persistent beyond the server; you have a Discord account, not a server account. Slack does the opposite. Enterprises would hate Discord's model, as they prefer to control the entire identity of every user in their systems, such that when they leave the company they can destroy any notion of that identity ever existing.

[joshstrange]

Absolutely agree. I like the 1 main discord account but I wish I could have 1 "identity" per-server as well. I don't love that I am in some discords that I don't want tied to my real name and others where I've known these people for over a decade and would see in person multiple times a week (before the pandemic). I know you can set your name per-server but you can't hide your discord username (or make it per-server) which sucks.

[LambdaComplex]

Agreed completely. Discord has always been much smoother for me than Slack, and the voice/video chat quality is literally the best I've ever seen anywhere. If they made their branding a bit more professional and changed the permission model from the (accurate) garbage you described to something closer to Slack then I think Slack would be doomed.

[davidwparker]

We use Discord exclusively at my day job.

We have a few bots we've integrated with things (deployment, stats, etc).

We use it for all our voice/video calls.

Edit: We've got roles setup well for things like contractors, devs, marketing, etc, so it's easy to lock down different conversations in channels.

It's been fantastic.

The only thing I'm not a huge fan of is the (IMO) poor implementation of threaded discussions.

Edit: it definitely has issues with connectivity from time-to-time too, but not bad overall.

TBH, I'm not sure why companies use Slack (I use it for other organizations, so have experience with it too, but not extensive).

[gruez]

>I didn't realize that Discord has way more active users than Slack

Keep in mind you're comparing daily active users vs monthly active users. I'd guess most slack users are online weekday for pretty much the entire day (because it's for work and your boss expects you to be online), whereas a good chunk of discord users are only logging in a few hours a week when they're gaming.

[013a]

At 12:00pm EDT on a workday:

Minecraft official server: 190k online users. | Fortnite official server: 180k online users. | Valorant official server: 170k online users. | Jet's Dream World (community): 130k online users. | CallMeCarson server (YouTuber): 100k online users. | Call of Duty official server: 90k online users. | Rust (the game) official discord: 80k online users. | League of Legends official server: 60k online users. | Among Us official server: 50k online users.

Their scale is insane. Even with their usage spiking during after-hours gaming in major countries, their baseline usage at every hour of the day, globally, makes it one of the most used web services ever created.

Slack's DAU and MAU numbers are probably pretty close to one-another. Discord's MAU/DAU ratio is probably bigger than Slack's. That just means that Discord is, again, solving a harder problem; they have much bigger (and more unpredictable) spikes in usage than Slack. Yet, its a far more stable and pleasant product.

[jhgg]

Our secret sauce is Elixir/BEAM and Rust :)

Well for the real time side, I can't tell you how big a boon it's been to build our platform on top of Elixir/BEAM. Hands down the best runtime / VM for the job - and a big big secret to our success. Where we couldn't get BEAM fast enough - we lean on rust and embed it into the VM via NIFs.

2021 is the year of rust - with the async ecosystem continuing to mature (tokio 1.0 release) we will be investing heavily in moving a lot of our workloads from Python to Rust - and using Rust in more places, for example, as backend data services that sit in front of our DBs. We have already piloted this last year for our messages data store and have implemented such things as concurrency throttles and query coalescing to keep the upstream data layer stable. It has helped tremendously but we still have a lot of work to do!

To help scale those super large servers, in 2020 we invested heavily in making sure our distributed system can handle the load.

Did you know that all those mega servers you listed run within our distribution on the same hardware and clusters as every other discord server - with no special tenancy within our distribution. The largest servers are scheduled amongst the smallest servers and don't get any special treatment. As a server grows - it of course is able to consume a larger share of resources within our distribution - and automatically transitions to a mode built for large servers (we call this "relays" internally.) At any hour, over a hundred million BEAM processes are concurrently scheduled within our distributed system. Each with specific jobs within their respective clusters. A process may run your presence, websocket connection, session on discord, voice chat server, go live stream, your 1:1/group DM call, etc. We schedule/reschedule/terminate processes at a rate of a few hundred thousand per minute. We are able to scale by adding more nodes to each cluster - and processes are live migrated to the new nodes. This is an operation we perform regularly - and actually is how we deploy updates to our real time system.

I was responsible for building and architecting much of these systems. It's been super cool to work on - and - it's cool to see people acknowledge the scale we now run at! Thank you!! It's been a wild ride haha.

As for scale, our last public number perhaps comparable to Slack is ~650 billion messages sent in 2020, and a few trillion minutes of voice/video chat activity. However given the crazy growth that has happened last year due to COVID - the daily message send volumes are well over the 2 billion/day average.

[kevinqi]

Assuming this is real - very interesting read, thanks for sharing.

[screye]

Just anecdotal, but as someone who has used Teams continuously for 1.5 years, I can say that it has never been down for me.

That being said, individual instances of the app are notoriously unstable causing random annoyances. But, I am on a very early build of Teams, which is buggy by definition.

[gmmeyer]

Slack and the others have different contractual guarantees and different regulatory environments. Comparing them is not really fair because the reality is that these other services probably just lose tons of messages and slack/teams can't do that! They have to have better guarantees.

[radlad]

IME, Slack is far more likely to lose my message than iMessage. I believe that's part of the point being made above.

[gmmeyer]

I've never had slack lose a message when it's up

[radlad]

That's kind of the definition of a service being up. :) I've experienced numerous "soft" outages which result in messages not sending and getting lost - and even more double sends, sometimes very distant from where the message was originally sent.

ITT: Anecdotes

[gilbetron]

It isn't just # of users, though - SlackOps is probably unique to Slack in that list (minus Teams, I guess) - so # of messages per month is a better metric. Not that I'm letting Slack off the hook, it still may be that their codebase and/or dev process is just nasty.

[ffpip]

Telegram is closer to 500 million now.

https://t.me/durov/142