Facebook: Hacking All Night to an IPO

By the time Facebook shares start trading at 11 am ET, many Facebook employees will be exhausted and ready to go to sleep. All through the night Facebook headquarters was hopping and packed with people.

Mark Zuckerberg speaking at Facebook's Hackathon
Francis Luu | Facebook
Mark Zuckerberg speaking at Facebook's Hackathon

It wasn't a traditional party — but a Hackathon — the company's 31st. Even in the dead of the night- 4 am — there were over 500 people coding and taking breaks for a game of street hockey.

What's a Hackathon? It's a Facebook tradition — staying up all night coding, fueled by red bull, chinese food, and the excitement of everyone pulling an all-nighter together. The idea is to use the time to create products and work on ideas outside your day job. It was Hackathons like this one that produced the "Like" button, Facebook chat, and the precursor to Facebook's time line.

We hear that one product here last night is an app called "Lunch Roulette." Employees can submit their name to the app to be invited to lunch with a random group of their colleagues, invented as a way for Facebook's growing number of employees to meet each other. We'll see if this is something Facebook decides to offer more broadly on this platform.

This is a tradition that goes back to Facebook's earliest days. When at Harvard Zuckerberg and his co-founders would go on what they called "Lockdown" — staying up all night coding before rolling the service out to additional colleges."

Zuckerberg kicked off the event last night in front of a new jumbotron in the headquarters main courtyard, called "Hacker Square."

Zuckerberg made some comments and hosted one of his regular Q and As with employees — he does one every Friday. On Facebook, employees posted photos of the excitement and said it reminded them of the inauguration.

Based on how packed Hacker Square looks from the arial shots — the opening bell ringing will have a similar feel.

Last night employees took turns DJing, and partook of plenty of food, red bull, and even beer. After Zuckerberg's comments people spent some time forming teams — engineers, designers, project managers, between heading off to get to work. And it's not all coding — there was a big game of street hockey, with employees rotating in.

Zuckerberg rang the opening bell at 6:30 am PT along with Nasdaq CEO Bob Greifeld. The countdown was broadcasted to Facebook employees in offices around the world. Most employees don't usually arrive until 9:00 or 10:00 am, but today early busses brought employees in from San Francisco around 5:00 and 6:00 am.

This is an exciting moment — and not just because today's events will make many of the 2500 employees at the headquarters very wealthy.

-By CNBC's Julia Boorstin