Business Insider/Julie Bort
It turns out that Facebook's famous motto, "Move Fast, Break Things" isn't such a good idea, he told attendees at F8 Developer's conference on Wednesday in San Francisco.
"This wasn't actually helping us move faster because having to slow down and fix these bugs was slowing us down more than we were actually improving our speed," he said. "'Move Fast With Stable Infra'...it might not have quite the same ring to it, but it helps us build better experiences."
In other words, Facebook is now doing what ever other company on the planet does: work as fast as possible without breaking stuff. Because working so fast that you break stuff actually slows you down.
This could - and should - have a major ripple effect across the whole tech industry, particularly other cloud app providers. Many of them followed Facebook's lead and adopted their own "move fast, break things" philosophy, and now they've been warned that it doesn't work.
Secondly, Facebook is finally (sort of) giving up on the idea that it's better for people to use their real identities online.
Remember, Zuckerberg is the guy that famously said: "Having two identities for yourself is an example of a lack of integrity."
But on Wednesday, Facebook announced that it will soon let people log into third-party mobile apps anonymously.
Before Facebook, no one used real names online, they used made-up user names. Even now, using a fake name on Facebook is a violation of its Terms of Use.
So when you use Facebook to log into apps and websites, developers can collect all kinds of information about you.
That stance led to the rise of a number of Facebook alternatives like WhatsApp, which Facebook bought for $19 billion because it looked like the app would one day reach 1 billion users. Meanwhile, anonymous social networking apps like Secret, Whisper, and Yik Yak are growing in popularity.
Turns out, people still want to control what they share about themselves online.
With Facebook's new anonymous login, the user gets to control how much data - if any - gets shared with the app developer.
Notice that Facebook is not offering an anonymous option for Facebook accounts.
Nevertheless, both of these changes represent a maturing of Facebook and its young billionaire co-founder, who will turn soon turn 30.
That's good for Zuckerberg. It's good for Facebook. It's also good for the people that use Facebook.