Tap2Card
LiveThe digital business card you share with a tap.
Tap2Card replaces the paper business card.
Built with
- Kotlin
- Jetpack Compose
- Swift
- SwiftUI
- Supabase
- NFC / HCE
- Room
- Koin
Winterthur, Switzerland · Open to conversations
Marko
Nonninger
Senior Mobile Engineer — iOS & Android
Ten years of building mobile apps people depend on every day: a banking app that moves more than a million transactions a week, a marketplace used by 300,000 people a month, and apps of my own shipped end-to-end to the App Store and Google Play.
I have led a mobile team, modernised nine-year-old codebases, and still write the code myself. If you are hiring, or need someone to build your mobile product, let us talk.
- 10+ Years in mobile development
- 1M+ Weekly transactions in production
- 300K+ Monthly users served
- 99.85% Crash-free rate achieved
Profile
Mobile is not a side skill for me. It is the craft.
I build Android and iOS applications from the first architecture sketch to the store release — and I stay responsible for them afterwards. Most of my work has happened in environments where mistakes are expensive: Swiss banking, a large automotive marketplace, automotive engineering.
What I bring beyond the code is the ability to hold a product together. I have run agile ceremonies as Scrum Master, led the “Autobots” team at Scout24 including people management, and worked shoulder to shoulder with UX, backend and analytics. At ZKB I introduced a future-proof architecture and led the refactoring of components that were over nine years old.
In my own time I ship my own apps. That is deliberate: owning a product end to end — design, architecture, backend, store release, support — keeps me honest about what actually makes software work in the real world.
Own apps
Products I built and shipped myself
Designed, developed and released solo — from the data model to the store listing.
Ausgetrunken
In developmentWine discovery, and the tools for the wineries behind it.
A two-sided app for wine lovers and winery owners.
Built with
- Kotlin
- Jetpack Compose
- SwiftUI
- Supabase
- Google Maps
- Play Billing
Currently in development — heading for Google Play and the App Store.
5 Skills
Open sourceAn Android reference project, in the open.
A compact Jetpack Compose app for tracking the five skills you want to grow.
Built with
- Kotlin
- Jetpack Compose
- Hilt
- Firebase
- Clean Architecture
Career
Where I have done this
-
Senior Android & DevOps Engineer
Zürcher Kantonalbank — ZKB TWINT
I develop and maintain the ZKB TWINT Android app.
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Software Engineer Mobile · Team Lead
Scout24 Schweiz AG — AutoScout24
I built and maintained the AutoScout24 Android app.
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Mobile Developer
Daimler TSS — App Creation Center
I developed iOS and Android applications across client projects.
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Mobile Developer
let’s dev GmbH
Trained and hired as an iOS and Android developer.
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B.Sc. Computer Science and Media
Hochschule Karlsruhe (HsKA)
Software engineering combined with design and media production.
Skills
What I work with
Ten years of tools, patterns and habits.
Mobile engineering
- Kotlin
- Java
- Swift
- Jetpack Compose
- SwiftUI
- Kotlin Multiplatform
- Coroutines
- Flow / StateFlow
- LiveData
- Room
- Paging
- CameraX
- Navigation
- NFC / HCE
- Android Studio
- Xcode
Architecture & quality
- MVVM
- Clean Architecture
- UseCase + Repository
- SOLID
- TDD
- Legacy modernisation
- Dagger
- Hilt
- Koin
- Gradle
- Git
Backend & DevOps
- Backend-for-Frontend
- Supabase
- Firebase
- REST APIs
- Retrofit
- OkHttp
- Ktor
- Postman
- Fastlane
- CI / CD
- AppDynamics
- Store releases
Leadership & collaboration
- Team Lead
- Scrum Master
- People management
- Developer growth
- Agile facilitation
- Cross-functional work
- Stakeholder communication
AI-assisted development
- Claude Code
- MCP servers
- Agentic workflows
- Prompt engineering
Design & UX
- Figma
- Zeplin
- Sketch
- Photoshop
- Material 3
- Human Interface Guidelines
- UX testing
Work with me
Two ways to start a conversation
For recruiters & hiring teams
I am open to senior and lead roles in mobile engineering.
- Senior / Lead Mobile Engineer, Android-first with iOS depth
- Team lead and Scrum Master experience, including people management
- German (native) and English (business fluent)
For companies & founders
I take on selected freelance and contract work.
- App development from concept to App Store and Google Play release
- Architecture reviews and modernisation of legacy mobile codebases
- Technical sparring, code reviews and team enablement
Contact
Let us talk.
Whether it is a role, a project or just a technical conversation — write to me and I will answer.
-
Email
contact
@markono.dev - LinkedIn marko-nonninger
- GitHub MarkoNo-Code
- Based in Winterthur, Switzerland
Full CV available on request.