Oliver Zilken, Computer Science

Outsiders usually don't understand much about computer science: lots of incomprehensible code that miraculously comes together to form functioning software. Hardly anyone realises the complex processes behind such, ideally very simple, software. You might imagine a dark room in which computer nerds sit in front of their screens and incessantly type in numbers and letters.

But when you enter the Rewe Digital site in Cologne, where Oliver Zilken works, it looks completely different: A wide, open space, plants everywhere, the white walls are covered with small greetings and complicated tables. On the way to his workstation, the 1.91 metre tall Zilken is greeted by many and asked how he is doing. With his relaxed manner in a white shirt, jeans and slightly tousled blond hair, he shakes a lot of hands. Just like among friends. At Zilken's workplace there is a note that reads: "The best Olli."

Only small details indicate that software is developed here. Several crates of particularly caffeinated Club Mate iced teas, for example, and large Android and Apple icons on the walls. "We are currently developing the shopping app for Rewe, one version for Apple and one for Android." Rewe Digital is a subsidiary of the Rewe Group that develops all the necessary software for the retail giant. The employees use the so-called Scrum approach. This means that they work exclusively in teams and each team has a number of tasks that it can work on. The essence of Scrum is that many requirements and solution approaches are not clearly defined at the start of the project, but are developed by the individual teams in their areas based on their direct experience. In the software sector in particular, this often leads to better results in the end, but this project management method is now also used in many other sectors of the economy. On average, there are eight to ten employees in a team at Rewe Digital and they all sit at the same table. "Direct communication and openness are very important in order to make good progress as a team," says Zilken.

A good end product requires different parties in software production: one that thinks about profit, i.e. wants to see successful software. One that is responsible for the visual appearance, so that the software also appeals to the customer on the outside. And there are the IT people who take care of the background: What happens when I click here, what happens there. In the outdated software development process, these teams were separate and communication essentially only took place via the project manager. He could make decisions on his own, but also had to take responsibility.

Scrum works differently: someone from each party is represented in a team. There are the specialists, the developers and the designers. One person, known as the product owner, is responsible for communication between the team and those responsible for setting the requirements. The last member of the team is the Scrum Master, the role played by Oliver Zilken. He takes care of the atmosphere between the people and moderates the meetings. It's very much about the personal, the human element. "From time to time, you're the doormat for the others, but it's still a lot of fun. I don't take it personally, it's my job."

The team selects a task together and works on it together. As every piece of software, in this case every app, consists of many small building blocks, each small building block is also worked on individually. One building block for the Rewe online app, for example, is logging into the account. The team is now developing everything for this: the look, the functions, the codes. This part is then presented to testers who evaluate it. The module is returned to the team with any points of criticism. This results in much more intensive communication between developers and testers - and not just when the app is finished. "This way of working isn't any faster," explains Zilken, "but ultimately it's more effective because we know directly what people want."