Borussia Dortmund



Android development


Android, RxJava, Push


Lagardère Sports


2015 – 2016

What was Karlmax’s role in the project?

We took over the technical maintenance of the project and embedded new features and optimisations.

Why does the user need the app?

Because it makes the football heart beat faster

What can the app do?

News, current hot gossip or how to get to the fan shop–all this is to find in the app just a click away. Statistics, results and tables—from the most sacred (the football league table) through to the scorers–it’s all there at any time day or night.


The challenge

In technical terms, the app is run by a comprehensive architecture, which uses RxJava to handle the entire array of live communication including Push and API connectivity. On game days, more than 100,000 users need information and results at the same time (especially those not lucky enough to make it into the stadium), and at such times the entire infrastructure is required.

Then there is the integration of social media, and that’s in both directions: coming in, an up-to-date stream of associations, players and correspondents; going out, fans sending tweets or posts during the game, sharing their excitement in real time.

How did we proceed?

We took over the app from our colleagues at the Rheinfabrik, and together with Lagardé Sports are developing it ever further. The first big innovation was the integration of the so-called “Feiertach” (Public Holiday), where a special service was provided for all users on game days. Now, new versions with small improvements are released each month.
Needless to say, the app being rated by WIRED as the second-best football league app is a great motivation.


Behind the scenes or: How I was suddenly sixteen again

Even when a release, thanks to automated builds and proven test routines, is no longer such an adventure, the first new version for Borussia isn’t going to leave any Dortmund fan cold. If you’d stood in the crowd in 1995 at the Friedensplatz and witnessed their first football league victory, you too couldn’t help but have a fluttering heart the first time you hover the mouse over BVB and click ‘Publish’.

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