Yep, just like Whatsapp. That team had about 50 people when Facebook bought them and a billion or so users. Twitter as it exists today is complicated and bloated. Doesn't mean that that's the only way to do it.
I bet mastodon doesn't have thousands of very active committers. They are taking a lot of users right now. With a hacked together pile of ruby and javascript. Easy to forget that that is how Twitter once started out as well. The bloated org chart came later.
For one, the distribution patterns of Whatsapp are far more simple than Twitter. Whatsapp is mostly one-to-one and then one-to-some with groups (with those groups being limited to as little as 100 users at some point, the current 1024 user limit has only been implemented recently). Twitter is one-to-many, with "many" being "several million".
But also, how much time did Whatsapp have to get to that point? I'm not saying it's impossible, but that it's difficult and takes a lot of effort that shouldn't be underestimated.
> They are taking a lot of users right now.
And still less activity than Twitter, and with federation, and with some servers already locking new account creation (mastodon.social, the biggest one, doesn't let you create new accounts).
Again, it's not that it's impossible. It's that it's hard.
Isn’t the crucial difference with WhatsApp that it doesn’t store the actual message data? I thought that their servers just told what apps to send where. I may be completely off base here.
It's probably part of how they keep things simple. But you seem to imply that storing lots of data is hard. It doesn't have to be. I've worked with search teams that operate at a very large scale. You need lots of hardware but not necessarily lots of people.
The scale of Twitter is large but not enormous. Basically a few trillions of messages overall. Most of them pretty small. All of them immutable (well so far). And lots of images/videos with some CDN in front of that. It's a lot of bytes but not a whole lot of complexity. And a couple hundred million users and user profiles. I can think of a quite a few ways of dealing with all that.
What's hard is things like algorithms and good search. But that's a space where you can achieve a lot with a small and focused team with access to lots of hardware. And obviously this is also something where Twitter has maybe been a bit underwhelming and struggling. User growth and engagement stagnated years ago for them. This was not a healthy social network. It's not like they were nailing this. Throwing more people at the problem wasn't working.
I bet mastodon doesn't have thousands of very active committers. They are taking a lot of users right now. With a hacked together pile of ruby and javascript. Easy to forget that that is how Twitter once started out as well. The bloated org chart came later.