
Client
Telekom
Consultancy
Sensity
Status
Product launched
Citykey – Smart City Initiative by Telekom
In 2019, I joined the Citykey team as a contractor at the Telekom Innovation Lab in Darmstadt, Germany.
From 2019 to 2024, I led a multidisciplinary design team of 10 (designers, illustrators, web developers, motion designers) in building a unified smart city platform.
The goal: help German cities tackle the challenges of digitalisation and support municipalities in providing digital public services in line with the Online Access Act (OZG).

Phase One
Prototype
Challenge
German municipalities relied on fragmented, poorly maintained apps for services like event listings, defect reporting, surveys, and accessibility information. We had to bring them together into a single, native-feeling app for both iOS and Android.
Solution
Instead of following the common “one feature – one app” principle, we created a **polished one-stop solution**, replacing outdated standalone apps and delivering all services through a unified interface.
Additional Challenge – Flexibility vs. Consistency
As more cities joined, balancing municipal requirements with user needs became more complex.
We developed a **flexible branding system**:
- Neutral UI, customisable colours per city
- Consistent Citykey identity across all instances
**Design assets**
- Logo: *Cosmin Cuciureanu*
- Modular illustration system: *Lars Keller*

Logo designed by Cosmin Cuciureanu

Illustrations created by Lars Keller
Phase Two – Launch I
Citykey App
Challenge
The app’s wide feature set needed clear and engaging communication in order to encourage adoption.
Solution
We created motion design explainers that showcased the different features of the app in an approachable way — from defect reporting to citizen surveys.
Result
German tech press coverage was overwhelmingly positive.
Phase Three
Scalability
Challenge
Due to Germany’s federal structure, municipalities often rely on different IT infrastructures even when providing the same services.
Onboarding cities required manual API adjustments, which slowed down expansion.
Solution
We developed a **CMS-style backend system** to simplify onboarding and reduce developer overhead.
I supervised the UX concept and the UI design system for this platform.

Phase Four – Launch II
Citykey as a Service
Challenge
To scale further, we needed to communicate the value of the backend system to municipal employees, many of whom had little technical background.
Solution
After a successful beta phase, the CMS was launched as a SaaS product, allowing cities participating in the programme to onboard themselves.
Together with a copywriter and web developer, we created a second landing page tailored specifically to municipal staff, using clear and accessible language.
Conclusion
Working with the Citykey team was both challenging and rewarding. Over five years, we built a complex and scalable product that helps bridge the gap between municipal administration and modern digital expectations.
The journey continues as more communities adopt digital public services.
Contact.
Built with love in Cologne, 2026. Imprint