Akamai Helps Zalando with Cloud-Powered Load Testing

Take a quick look at your wardrobe. If you live in Europe, there’s a good chance you’ve ordered clothes or shoes from Zalando, one of the continent’s best-known online fashion and lifestyle platforms. Dig deeper amongst the T-shirts, jackets, and sneakers, and you’ll probably find a bargain that you grabbed during Cyber Week. 

While snapping up a holiday bargain might be thrilling for consumers, it is serious business for Heinrich Hartmann, Head of Site Reliability Engineering (SRE) at Zalando. His team is responsible for making sure Zalando’s IT systems are properly tested and ready for peak times. 

The challenge is even greater given the complexity of Zalando’s IT infrastructure. To meet the needs of 50 million active customers in 25 countries, Zalando runs 5,000 business applications across 200 Kubernetes clusters. Hartmann says, “Preparing for Cyber Week is a four-month, company-wide project with hundreds of engineers readying our infrastructure for load spikes that can be up to 10 times higher than usual as customers flock to the site.” 

But there’s more to shopping than just website performance. Each request to the Zalando platform can trigger thousands of calls to systems across the company. “It’s not just a web page latency or availability challenge,” says Hartmann. “We must ensure that all our event-driven systems are up to the task, from price update applications to downstream logistics and fulfillment.”

In the past, Zalando operated an in-house testing environment based on open source tools. But this proved challenging, especially when assessing cases based on thousands of datasets and test customers. “We invested a lot of effort and resources into load testing in the past,” says Hartmann. “It was time to look for another solution that made testing practical and scalable for a business of our size.”

Zalando already had helpful contacts at Akamai who recommended CloudTest, a real-time load testing tool, which uses the power of cloud computing to prove consumer-facing web and mobile applications at scale. Following a successful trial, CloudTest was deployed as an on-demand service, with an Akamai Performance Engineer embedded with the Zalando SRE team.  

Thorbjörn Gruda, Senior Principal Site Reliability Engineer at Zalando, says, “With Akamai, you can deploy a load test using hundreds of thousands of virtual users in minutes and quickly identify the slightest software bottleneck. Combined with real-time analytics, it gives our team enormous peace of mind in the run-up to Cyber Week.” 

CloudTest has also proved its capacity to scale in line with customer growth, especially the shift to digital commerce in the wake of COVID-19 lockdowns. “When we first started with Akamai, we were load testing the shop system with a few hundred thousand requests per second (RPS) for Cyber Week. This figure is now business as usual, and we expect to test two or even three times this amount in the future,” says Gruda. 

The SRE team was also impressed by the reach of its global CloudTest environment, which includes four CloudTest Operations Centers serving hundreds of customers from all industry verticals.

Zalando has so much confidence in CloudTest that it recently invested in an in-house license. Hartmann says, “CloudTest is now an embedded solution that can be used all year round by the majority of our engineering teams.”

Akamai Professional Services played a central role in the transition. “We joined them in workshops to ensure that we could take over CloudTest ourselves with minimal disruption,” says Hartmann. “The training helped engineers to familiarize with the tool. Every time they want to use CloudTest elsewhere in the business, we can point them to the Akamai sessions.” 

Hartmann is also impressed by the speed with which the Akamai team responds to technical queries. “Our contacts at Akamai will pull together a team of engineers at a moment’s notice, and we can jump on a call to get their advice. Our own people are increasingly proficient, but these are highly complex testing scenarios, so it’s good to know that Akamai has our back whenever we need them.”

The beauty of CloudTest is that it can be adapted quickly to different scenarios and testing timelines. Gruda says, “CloudTest allows us to do load testing on a larger scale due to its great feature set. As shoppers adapt to new technologies and lifestyle choices, we can support the wider Zalando business as it innovates to meet the needs of the next generation of online customers.”

Zalando is a leading European online platform for fashion and lifestyle. Founded in Berlin in 2008, we bring head-to-toe fashion to over 50 million active customers in 25 markets, offering clothing, footwear, accessories, and beauty. The assortment of international brands ranges from world famous names to local labels. Our platform is a one-stop fashion destination for inspiration, innovation, and interaction. As Europe’s most fashionable tech company, we work hard to find digital solutions for every aspect of the fashion journey: for our customers, partners, and every valuable player in the Zalando story. Our vision is to be the Starting Point for Fashion and a sustainable platform with a net-positive impact for people and the planet.