Moving To A Better DNS Neighborhood

Zillow | | HQ: Seattle, WA| Founded In 2005| Industry: Homes, Real Estate & Mortgage Content

With 70 million visitors monthly, listings for over 110 million properties, and a user community growing each year, Zillow faces greater website performance challenges than most online marketplaces. Thanks to Dyn, resolving DNS queries is not an area of concern for Zillow’s web team.

Who Is Zillow?

The leading real estate site in the United States, Zillow describes itself as the “marketplace where homeowners, buyers, sellers, renters, real estate agents and mortgage professionals find and share vital information about homes and mortgages.” Based in Seattle, WA, and publicly traded, Zillow’s revenue has continued to grow in recent years (89% increase in 2013 alone), and its quarter-over-quarter site visitor growth is 57%.

As such, it is not possible to overstate the importance to Zillow of 100% website availability and exceptional site performance.

In short, their 70 million-plus monthly unique users enjoy insight into the latest real estate listings, mortgage rates, rental information, connections to top professionals, and tons more, either on their desktop, laptop or mobile device.

And again, 70 million monthly unique users. That would be the 19th most-populated country in the world, more than the United Kingdom. In a month!

What Were Zillow’s Technical Needs?

  • Reliability
  • Honest and upfront support
  • A focused DNS company

How Did Zillow Come To Dyn?

The experience of working with an outsourced DNS traffic management provider usually goes one of two ways: effective and a pleasure, or ineffective and an annoyance. Just one bad experience — either with downtime, an ill-mannered support interaction, or a combination of both — can take a once fruitful relationship and sour it quickly.

Zillow (NASDAQ:Z) unfortunately dealt with all of the above and then some through a history of working with traffic management providers. As Zillow grew, their company had used a well-known domain provider that primarily caters to an audience with lighter traffic and very basic web management needs. As they began to get more attention, Zillow began to look around and made their first move to a more advanced company that offered free DNS service in conjunction with renting co-location space.

While seemingly ideal at first, the relationship began to turn dour.

“Every time we needed to make a configuration change, we had to call them,” Zillow Infrastructure Architect and Senior System Administrator Jerome Ibanes explained. “We also experienced bits of downtime, and had to submit tickets with four hour turnarounds for assistance. It was unbearable.”

Needing something that was more flexible, responsive, and real-time, 20-year industry veteran Ibanes began to search again. Part of his criteria was that Zillow’s new provider should be DNS experts, and not just offer it as part of a somewhat-related suite of technology software and applications. There were larger companies Ibanes considered, but wanted to feel like he and Zillow were an important part of a company’s book of business, not an overlooked line on a spreadsheet.

He could have sourced DNS service from his content delivery network (CDN) vendor Akamai, but wanted to work with a vendor focused on DNS.

“Dyn is different. Uptime is a big deal for them,” Ibanes explained. “If other companies have downtime, it’s not their core business, so they can survive the heat. If Dyn doesn’t do DNS right, they’ll go out of business.”

The company also evaluated bringing everything back in house, relying on hardware load balancers instead of a cloud-based solution. There were a few things that turned Zillow off to such an investment, especially as their traffic grew worldwide. Ibanes was looking at $100,000 a year in renewal costs for his existing setup, in addition to management costs. Going in-house wasn’t scalable and also wasn’t their core competency.

Their needs were simple: a solid DNS-focused company with traffic management friendly features that would free Ibanes from having to increase his workload.

What Made The Dyn Difference?

Zillow entered an agreement for Dyn’s Managed DNS solution, along with failover and load balancing, advanced features that are now part of Dyn’s Traffic Director. That service extended to their main website in addition to other sites they manage like and

For any Dyn client, the stakes are high, but especially for Zillow. In addition to their own site, they work with partners such as that rely on Zillow’s content to power their sites.

Ibanes appreciated the low latency and site responsiveness he immediately got with Dyn, as well as caching of DNS queries — something immensely important as they cache between 90-98% of their data. Even a two percent swing can cause big issues, something they found out when using other DNS services in the past.

“That unpredictable swing resulted in a load on our servers going from 50% to 200% at any time. It didn’t follow a traffic pattern, and they were unwilling to look into it. That was the quality of service we were dealing with. It was annoying.”

Ibanes added that he enjoys having support conduits like Dyn’s status page to go to if there are any issues with the network. The aforementioned competitor had a major outage which Zillow had to point out first, and when they did, they felt like the DNS provider was dodging questions and hiding behind the issues. It broke their trust immediately.

“With the status page, Dyn may not be proud something is happening, but it’s available to everyone. We like that transparency, something we didn’t have with other companies. They let us know when there’s an issue, and we really appreciate it,” Ibanes explained.

The Future

Plans are underway to open up another colocation facility in an effort to increase reliability and reduce latency for customers and partners alike. By using Dyn Managed DNS, they are confident about making that move.

“Dyn will play a big role in that. You don’t get the level of granularity with other companies that you do with Dyn. I can balance traffic from the east to west coasts, and balance everything depending on the server. It’s a big plus for us going forward.”

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Want to learn more about Managed DNS?

Zillow uses our Managed DNS with traffic steering capabilities. To learn more, check out our products section!

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