Sameday’s new Kubernetes-based infrastructure powered by Zitec faced the Black Friday test

Learn how Zitec helped Sameday migrate to a new Kubernetes infrastructure that efficiently handled the Black Friday campaign while delivering over 3.6 million orders.
Sameday’s new Kubernetes-based infrastructure powered by Zitec faced the Black Friday test

The partnership between Zitec and Sameday reached a new milestone in the fall of 2022 when the new infrastructure based on Kubernetes faced the ultimate stress test: Black Friday.

Sameday’s migration to a container-based architecture powered by Kubernetes was completed shortly before the Black Friday event. Given the size of their infrastructure, with more than 4500 lockers only in Romania and 34 application environments, the project posed certain challenges that were addressed by our DevOps team in order to meet the business objectives. This vast network needed to be powered by a robust infrastructure that could handle massive traffic spikes and be scaled up quickly as the company grows. 

Sameday is the fastest-growing courier company in Romania, thanks to its innovative network of Easybox lockers that has become the most popular delivery method for online shoppers. The huge success of this quick and flexible service allowed the company to expand outside Romania’s borders and enter the markets of neighboring Hungary and Bulgaria, where the number of lockers is growing swiftly. But Sameday’s ambitions do not end here: the company experiments with next-generation delivery methods, such as drones.

The challenge

Technological innovation has been an essential part of Sameday’s business model from the very beginning, the company relying on technology to become the largest and most innovative courier company in South-Eastern Europe. Over the past seven years, Zitec has been its strategic partner in supporting this vision and business growth. 

Sameday already had a reliable and elastic cloud-based setup powered by Microsoft Azure virtual machines that had proved its resilience in previous years. However, virtual servers are no longer considered a modern solution, because they lack the additional features, flexibility, and portability of container orchestration platforms.

As their long-term partner, Sameday entrusted us with the development of a modern infrastructure, based on ‌container architecture. They wanted an easily scalable solution, along with the possibility to use resources as effectively as possible and to optimize costs. At the same time, the solution had to allow multi-cloud deployments, without any vendor lock-in, so it could be quickly migrated on any platform if needed.

The migration process

An architecture orchestrated by Kubernetes came naturally for Sameday’s needs since it provides superior scalability and can be deployed on any cloud (or non-cloud) provider. 


The migration process required careful research and planning because several factors had to be considered, besides the technical aspects. The most important challenge was to complete the task without impacting the applications while allowing the development teams to continue their release schedules. At the same time, developers had to be trained on the new Kubernetes environments and were given time to become comfortable with them.

The final test - Black Friday

The new setup proved to be fast and stable but one major question remained unanswered: how will the infrastructure perform on Black Friday? This period of discounted sales, which marks the unofficial start of the Christmas shopping season, is the ultimate test for online retailers and courier companies, due to the massive and often unpredictable traffic spikes.

Our engineers were ready for the challenge, with 39 code releases on the 34 environments used by Sameday applications during the month prior to the event. The DevOps team optimized hardware resources, made sure all monitoring tools worked properly and followed a 24/7 on-call schedule to be ready for intervention if needed.

Despite a 20% increase in the total number of packages delivered by Sameday compared to Black Friday 2021 and a whopping 85% spike in the number of orders delivered to Easyboxes in the first four days, there were no major issues on the company’s applications or infrastructure during the entire event. 

The raw numbers speak for themselves: our partner delivered over 3.6 million orders, of which around one million in the first four days of the campaign to a network of 3650 lockers. Around 980,000 AWBs were created, over four million locker logs were processed and Sameday’s website was visited by more than 350,000 unique users.

The campaign’s impact

The metrics collected before and during Black Friday give us an overview of the performance of the Kubernetes setup and its advantages compared to the old infrastructure, which was hosted on virtual machines.

The main benefit, especially for a partner that can’t afford any downtime, is high availability. Built-in resilience is a key feature of Kubernetes since pods are self-healing and load balancing is automatic. While the legacy setup also provided similar capabilities, the performance of distributed containerized workloads is superior when there is a sudden increase in the number of requests. The engine kills and restarts any container that fails, while a classic server that has problems must be investigated and restarted manually by a system administrator. All of these contributed to no downtime for the Kubernetes cluster, even during peak Black Friday traffic spikes. 

  1. Cost reduction: when properly configured, Kubernetes can manage hardware resources effectively and provide a significant cost reduction. After the migration, the infrastructure cost of Sameday’s development environment went down by almost 40%. As for ‌production applications, even if the number of AWBs rose to 8.6 million in November 2022 compared to only 4.6 million in July, the infrastructure bill only went up by less than 20%.
  2. Improved scalability is another major advantage of ‌container architecture. Modern cloud-based virtual machines provide good autoscale options too, but Kubernetes does it much faster, which can prove critical during unexpected load spikes.
  3. Containerized applications are great for development as well. Changes can be deployed a lot faster, and developers can install the whole Sameday application suite on a Kubernetes cluster on their local machine, following a simple procedure. This creates an identical replica of the production setup, allowing programmers to focus on coding instead of troubleshooting various installation errors or dependency issues. 
  4. Superior observability: a modern monitoring suite powered by Kubernetes can process millions of log files and not only detect issues but predict them as well. As such, during the Black Friday 2022 campaign, Zitec developers and DevOps engineers were able to fix potential problems and tweak applications for optimal performance.

“Migrating to a container-based architecture helps us scale up and down individual parts of the ecosystem depending on the area that is more active during a certain time of the day, whether it is the warehouse or the last mile team, the Easybox team, etc. This is an important technical advancement as this way we can use the allocated hardware resources to their highest potential and get the maximum efficiency for what we are paying in terms of infrastructure.”

Cristi Pena, Chief Systems Analyst & Partner, Zitec

Preparing for the future

Continuous innovation is a core value of the Zitec DevOps team; we constantly improve performance and support the growth of our business partners. The potential of Sameday’s migrated infrastructure is even greater, so our engineers will continue to optimize it to support the company’s ambitious expansion plans in Romania and other markets. There are always new technologies to test and tweaks that can be applied to make an application perform increasingly better. For Sameday and our engineers, the preparation for Black Friday 2023 has already started, as we want to continuously contribute to the fastest and most convenient Easybox delivery process in the country.

Wondering how you can efficiently handle high-traffic campaigns? 

With over 19 years of experience in delivering innovative solutions for companies such as Flanco, Cars2Click, or Token Financial Technologies, our DevOps team is always open to discussing your next high-traffic campaign or infrastructure modernization project. Send us a message if you have any inquiries or want to learn more about driving business growth. 


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Dragoș Băldescu