Erlang Factory 2014 - That's 'Billion' with a 'B': Scaling to the Next Level at WhatsApp

My other favorite "scalability" study is from WhatsApp: [VIDEO] That's 'Billion' with a 'B': Scaling to the Next Level at WhatsApp (that walk title was create before the acquisition and was mean to imply message count, after the acquisition it got a secondary meaning). The one thing that is fascinating about it, is how small their team was compared to the volume and complexity of the operation.

Not sure why this comment saw a couple downvotes earlier. mbesto is correct: for most startups, most of the time, competitive advantage doesn't come from the underlying tech stack. To make a general statement, most things could be done similarly on any of several platforms. However, when product requirements match exceptionally well with a specialized technology, you can see things that would simply be infeasible or extremely tough using a different stack. WhatsApp + Erlang was one of those cases (watch this talk and imagine trying to recreate that system with only a handful of server engineers using any other tech: [VIDEO] ). Discord + Elixir appears to be another. Curious if anyone has any examples that spring to mind from outside the highly concurrent messaging space.

One of my favorite talks is by Rick Reed about scaling Erlang at WhatsApp. What an absolute savage. He flies through an articulate and in-depth curriculum on system performance and bottleneck mitigation. The talk is called "That's 'Billion' with a 'B'" and makes for a great lunchtime watch: [VIDEO]

Unrelated, but maybe interesting: WhatsApp was running Mnesia and made it work fantastically. Especially with such a small team of engineers. Here is a video of Rick Reed talking about how they did it (hint it is not a one monolithic Mnesia cluster). [VIDEO]

Just to follow up on topic of WhatsApp and Erlang, here is a presentation given at Erlang Factory 2014 about their goals with scaling WhatsApp to billions of simultaneous users. [VIDEO]

Not "parent" but search for Erlang Factory talks they talk about it. Here is one from Rick Reed. He explains how the product works : [VIDEO]

It's required because your phone is where your messages are stored. Whatsapp don't retain messages/media after they've been delivered to your phone, which is a compelling privacy feature for many. It's also what allows them to serve such an enormous user base with limited hardware. Their technology stack (FreeBSD/Erlang) is pretty interesting, more info here: 2014 talks by Rick Reed: [VIDEO] [LINK] Slides: [LINK] There's likely no technical reason why you couldn't use a pc instead of a phone for users that want to use the pc as the primary client (with the phone optionally accessing the DB on the pc in the same way that the desktop client does for the phone). Perhaps they've decided that this is a small and declining market. Edit: Slides for second talk [LINK] 440k connections/sec, 1.1 million msgs/sec, 1 billion images/day, and that was in 2014...

Here's a great talk from Rick Reed (a former mentor of mine at Yahoo!) about how WhatsApp scaled their Erlang infrastructure: [LINK] Here's another talk: [VIDEO]