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Cross-Platform Development

One component. Three platforms. One look-and-feel.

React Native and Flutter — compiled to iOS, Android and Web. Native performance, shared logic, platform-specific polish.

Plan a cross-platform app

Stack choice

Which framework, when?

We ship both frameworks in production. The choice follows the project — not the favourite tool. Here is how we decide.

React Native

JavaScript · 0.85 New Arch

Strengths

  • Huge JS ecosystem, shared logic with web possible
  • Hot reload and fast iteration
  • Native modules for platform-specific APIs

Trade-offs

  • Bridge layer can bottleneck (Old Arch)
  • High-frame-rate animations may need native code

Fit

When your web team contributes, or when existing React codebases should be reused.

Flutter

Dart · 3.x

Strengths

  • Own rendering engine — pixel-perfect UI on every platform
  • Consistent 60fps animations out of the box
  • Strong tooling for design systems

Trade-offs

  • Dart as an extra language in the stack
  • Larger app bundles than RN

Fit

When UI consistency and animation are the priority — branded consumer apps and tooling.

What we deliver

Three concrete delivery standards

Cross-platform is not a promise. We deliver on three hard bars — measured, documented, signed off.

Code sharing
80–95%
Share of logic that runs identically across platforms.
Cold start
< 1.8s
On mid-tier iPhone and Pixel — measured with the production bundle.
Bundle size
< 30MB
iOS .ipa and Android .aab after tree-shaking and asset optimisation.

By the numbers

This is hafencity.dev

15+ Experts

Engineers, designers, and strategists working as one practice from our Hamburg HQ.

50+ Clients

Companies across consumer, healthcare, and B2B trust us with their digital products. Long-term partnerships are the default.

97% Recommendation rate

Repeat engagements and references our buyers actually call. Trust compounds when delivery does.

50+ Launches

Custom mobile and web products shipped from concept to maintenance — owned end-to-end by our team.

100% In-house

Strategy, design, and engineering all live at our Hamburg HQ. One team, one project lead, accountable to you from kickoff to launch.

Since 2023

Helping companies ship digital products — and growing alongside the teams we work with.

Next steps

Let's talk about your project

Book a 30-minute discovery call. We'll review your goals, surface unknowns, and outline how we would run the engagement.

Schedule a call