Zorg en Gezondheid


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Contact Tracing has been a hot topic for the past few years. Though it is commonly viewed as a crucial tool in our fight against the pandemic, organization at a semi-industrial scale requiring collaboration with multiple actors was entirely new. That’s why Zorg & Gezondheid, a Flemish government service, developed a new platform called SUM, “Samenwerkingsplatform Uitbraak Management”.

Carlo, one of our Optis experts, is one of the developers of the platform, so naturally we wanted to know what it was like to work on such an important project. Carlo has been with us for 4 years after graduating, but his preference for short term projects has brought him everywhere from small startups to large companies like Proximus.


Because both the viral and political situation are constantly shifting, speed was of the essence. An MVP-based approach was therefore absolutely crucial to ensure the platform was still relevant by the time development was finished.

The basic idea is simple; SUM is a cooperative work distribution system. Initial contact is done by call centers through an external system. If more in depth contact tracing is needed workorders are generated for the primary carezones where potential clusters are located.

Sounds simple, but the most important feature of the platform was the need for cooperation between relevant parties, such as the Flemish team of Infection prevention and the local Covid-19 teams. Connecting those dots required a lot of technical expertise and careful data curation, but also stakeholder coordination, which proved to be an absolutely essential tool to determine feature prioritization.

Using a microservice architecture and leveraging managed services they created a reusable and durable setup that can also serve as a kickoff for future projects.

The platform also needed to become more and more flexible as different types of workloads needed to be added and more parties started tor ely on SUM for their daily operations. Using a microservice architecture and leveraging managed services they created a reusable and durable setup that can also serve as a kickoff for future projects.

Carlo: “For example, we got reports that the search functionality was becoming sluggish as the daily workload and the amount of data began to grow. After some digging, we concluded that there was no efficient way to improve the default search implementation and switched to OpenSearch instead, a scalable AWS-managed implementation of Elastic Search. It’s very interesting to work on a platform that grows so rapidly, because it forces you to rapidly identify, diagnose and resolve scaling issues."


As previously mentioned, the unpredictable nature of the pandemic also had an impact on the development process.

Carlo: “Though some may find it frustrating, I actually enjoy the process of working through the changing priorities with our team. Sometimes, a feature needed to be implemented by the end of the week no matter what, so we switched our focus and made it happen. Though this flexibility came from both sides, our stakeholders were very understanding of this situation. Often intermediate solutions or alternatives were accepted and implemented.”

SUM relies heavily on data curated through a central data lake, snowflake was used as driver for most of the work generated in the webapp, and for this infrastructure and data we worked side by side with specialized data analysts from KPMG who took on a supporting role. Analyzing, defining, and prioritizing businessneeds as well as scope management and communication was done by Zorg &Gezondheid, who were supported by dedicated business analysts and project managers from KPMG. The collaboration of these different profiles together with full-stack developers and DevOps specialists from Cronos was imperative to the success of the project.

Though Carlo is currently still working on the platform, he can already look back on a rewarding experience: “The pandemic is something that affects us all, and it is really cool to have participated in a project that has made such an impact!”

Inspired by this story? Would you like to appeal to our software development skills? Don’t hesitate to get in touch and let’s talk business!

Carlo Nomes

February 17, 2022

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