The SumUp Tech Radar

The SumUp Tech Radar helps our teams choose the best technology for new projects, any time technology choices need to be made. Based on the pioneering work of ThoughtWorks, and using the visualisation library from Zalando, our Tech Radar tracks the technologies that we currently use in production.

There are more than 400 people working in 60 squads across Engineering and Product at SumUp. Alignment, especially related to technology decisions, in such a large organisation, is not an easy task. That’s why, seeing the huge potential of a successful Tech Radar, I decided to drive the project forward.

Why does SumUp have a Tech Radar?

As well as efficient alignment, uncovering the strengths and weaknesses of these technologies helps our teams avoid having many different tools for the same job, narrows down the best choices and builds deep expertise across the company through experience. This makes SumUp an altogether more resilient engineering organisation.

Technology is always evolving. Similarly, companies need to adapt and diversify the technologies they use. Our Tech Radar helps us introduce new technologies at SumUp, in a safe way based on risk assessment.

Whenever a team starts a new project, they can use our Tech Radar to research and find inspiration for software, with the pros and cons of each fully explained. Our engineers can learn from other teams and companies using the technology, helping to minimise pitfalls whilst amplifying successes.

And when engineers successfully use new technology in production, we acknowledge this by adding it to the Tech Radar.

But where new technologies emerge, others can fade away. Open source projects we use may no longer be supported with regular bug fixes, leaving us exposed to security vulnerabilities. We use our framework to be able to identify these technologies and migrate away from them.

What does the Tech Radar look like?

To reflect the current state of technologies used at SumUp we use four rings with the following designations:

Adopt — These are technologies that we’re very confident can serve a particular purpose and on a large scale. These are low risk and recommended for wider use.

Trial — We’ve successfully used these technologies to solve a real-world problem, discovering benefits but also uncovering certain limitations. Trial technologies are riskier. Engineers are able to share their knowledge and experience, but the technology should be investigated further before a wider adoption across SumUp.

Assess — Technologies in this ring are promising and have clear potential for us. It’s worth researching these further. Assess technologies have a higher risk. They’re often new and unproven within the company. You’ll find some engineers that have previous experience with them but these technologies should not be adopted without further evaluation.

Hold — These technologies aren’t yet worth further investment and should not be used for new projects. Hold technologies can usually, however, continue being used for existing projects when it’s too costly to migrate.How did we agree on the initial version of the Tech Radar?

I began with the research stage, setting up interviews with engineers and their leaders from each tribe. One of the things I love about working at SumUp is that whenever a good idea is suggested, with clear value and purpose, everyone helps to make it happen. This was an incredibly useful experience. I discovered even more about the great people I work with, as well as the technologies they use each day.

From these interviews, I then made a list of every technology used in production at SumUp. I divided these technologies into the agreed quadrants and created a spreadsheet, centralising the data.

I wanted to make sure that everyone had the chance to contribute, and I knew that buy-in from all our engineers was going to be important for the project’s success. In our Engineering and Product All Hands meeting, the time came for me to share an initial visualisation of the Tech Radar with my colleagues.

This early version was, of course, incomplete, and I still needed help assigning each technology to a ring.

In a follow-up meeting with representatives from each tribe, we discussed every technology individually, focusing on metrics such as suitability, adoption, or how long it’s been in use at SumUp.

One of our main challenges was deciding what technologies to put in the Hold ring. An example of such a technology is the Ruby programming language. Back when SumUp was still a small startup, Ruby served us really well. But in creating the Tech Radar it became clear that at our current scale, we couldn’t move forward with Ruby, instead favouring statically typed languages like Golang. Assessing each technology in this way meant that we were soon able to fill in all the rings of our Tech Radar.

At SumUp, we’re proud of the technologies we use. The Tech Radar showcases our commitment to the continuous improvement of software and processes. Now it’s time to share it with the world and create more transparency, hopefully inspiring others to undertake similar initiatives within their engineering teams.

It’s important that the software we use is reliable and of the quality expected by our engineers when they come to work at SumUp. The Tech Radar ensures that we’re able to develop the great work of our colleagues, attract new talent to SumUp and continue supporting small businesses to be successful doing what they love.