How Zoom pulled off the scaling event of a lifetime

All modern enterprise tech companies plan for scale. Few have been tested to the degree that Zoom was at the outset of the worst pandemic in modern history.

In December 2019, 10 million people a day participated in a meeting on Zoom. By March 2020, that number had grown to 200 million as governments imposed lockdowns around the world in hopes of containing the spread of COVID-19. And during the 90 days between Feb. 1st and April 30, Zoom experienced a 224% increase in the number of customers with 10 or more employees using its product compared to the previous 90-day period.

By and large, Zoom was able to handle that surge in demand with minimal service disruption, thanks to a global hybrid cloud network of self-managed data centers and the cloud resources of AWS and Oracle.

"There's a lot of things in terms of the way that we design the platform that enabled us to really scale in this situation," said Brendan Ittelson, chief technology officer at Zoom, in an interview with Protocol. "If we need additional data center capacity, we have the ability to quickly deploy it, and ramp up in either our data centers or with our public cloud providers so that we can scale that way."

Zoom's videoconferencing application was designed to make use of multi-bitrate encoding, which allows the application to provide different levels of video quality depending on local network conditions and demand, Ittelson said. That meant Zoom could still provide service to homes around the world that didn't necessarily have the same types of high-bandwidth video connections commonly found in commercial office districts without falling over, even if the quality wasn't superb.

For the most part, the company uses its network of 19 co-located data centers around the world to service meeting traffic, Ittelson said. Going into 2020, those data centers were running at about about 50% of peak capacity, he said, which gave Zoom the ability to absorb the early impact of increased demand in China and Europe as the pandemic spread.

Zoom's goal all along was to provide its services as close to the end user as possible through these data centers. Distance is an extremely important factor for video applications, given that stuttering video feeds and audio gaps caused by latency can ruin a big meeting in a hurry.

But Zoom is also a longtime customer of AWS, and uses the cloud provider's network for other parts of the Zoom application. During a video discussion in April , Zoom CEO Eric Yuan said that before the pandemic, Zoom was using AWS for pre-meeting and post-meeting activities , but started using AWS servers for meeting traffic as the impact of the pandemic became clear.

And Zoom customers aren't using the service for meetings alone.

"Zoom is a pretty wide product offering," Ittelson said. "We have the meetings, webinars, our Zoom Phone product, our Zoom Chat product … naturally, [in] the infrastructure for each of those, we use a range of components. There is everything from virtualization to bare metal in these different environments."

Zoom added Oracle as a cloud supplier in April as demand for its service skyrocketed and Oracle dangled price incentives, but Ittelson declined to talk about how Zoom assigns workloads between the two cloud providers, who don't like each other very much.

In November, Oracle co-founder and CTO Larry Ellison claimed that "the majority of Zoom meetings — these tens of millions of Zoom meetings that happen every day — happen in the Oracle cloud," which doesn't square with Ittelson's description of the role Zoom's own data centers play when it comes to serving meeting traffic. Both AWS and Zoom CEO Eric Yuan have also disputed Ellison's claims about Oracle's role inside Zoom's infrastructure strategy.

Buoyed by a surge in revenue during the first half of 2020, Zoom is planning on reinvesting that windfall in its own data center capacity over the coming months, Yuan said on the company's second-quarter earnings call. Zoom has added data centers in Osaka, Japan, and Singapore since the initial surge in February and early March, and announced plans back in September to invest in the capital expenditures required to increase that footprint.

As Zoom nears the end of a year that few of us will ever forget, it's being cautious about what it expects for 2021, during which a COVID-19 vaccine is expected to become available and life in North America and Europe will hopefully start resembling something normal.

While it's unlikely that Zoom will experience the type of all-hands-on-deck scaling event it saw in the first part of 2020, it's also unlikely that demand for videoconferencing services will fall off a cliff. Microsoft co-founder Bill Gates told attendees of the virtual New York Times DealBook conference in mid-November that he expects business travel will fall by half over the foreseeable future. That will make for lots of additional virtual meetings to come — and probably plenty more opportunity for Zoom to grow.

"I think there's a new range of things that will come out, and we're not going to go back to the way it was," Ittelson said. "We're excited to see where folks continue to shift."

Correction: A previous version of this story used the wrong metric for Zoom's use. It measures use via daily meeting participants, not users. Updated Dec. 10, 2020.