
Erlang Solutions
6 HN recommenders · recommended in 14 months, 2014–2022
49:15 · 50K views · Mar 8, 2014
Rick Reed of WhatsApp explains at Erlang Factory 2014 how the service scaled to billions of messages with a very small engineering team. He covers the FreeBSD and Erlang stack, Mnesia usage, server counts and bottleneck work.
The go-to talk showing how Erlang let a tiny team run a massive messaging system.
15 comments from Hacker News
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: this video ). Discord + Elixir appears to be another. Curious if anyone has any examples that spring to mind from outside the highly concurrent messaging space.
My other favorite "scalability" study is from WhatsApp: this 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.
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: this 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: this 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 is the description of their stack and how Erlang helped them by Rick Reed at Erlang Factory: this video Here is Jamshid Mahdavi talking about their stack as well but focusing on development, testing and shipping code. Some of the stuff they do will surprise you if you've been at a shop with a large QA team and deployment pipelines with many stages. [LINK]