SDK Zurich City Guide App

I owned the implementation and technical coordination of an embeddable React Native SDK that brought Holoai’s Joaia guide into Zürich Tourism’s live iOS and Android apps.

zuerich.com

Project at a glance100K+ downloads · live in production

RoleSDK engineer · technical coordination

ClientZürich Tourism · Holoai / Joaia

PartnerBinarium (integration)

DeliveryEmbeddable SDK · iOS · Android

Core stackReact Native · Swift · Kotlin

Timeline2026 · ~3 months · 4 milestones

The challenge

Zürich Tourism wanted to add Joaia’s conversational AI guide to its established City Guide apps. The guide supports voice and text chat, follow-up questions, and local recommendations.

Binarium maintained the native apps, and I had no access to their source code. The SDK therefore had to behave like a clean external dependency, integrate without disrupting the live product, and connect to existing native features such as maps and favorites.

The hardest engineering problem was lifecycle coordination. Cold and warm starts differ across iOS and Android, while users move repeatedly between native screens and the React Native SDK. Navigation and shared state had to remain reliable in every entry path on both platforms.

My role

I took technical ownership of the SDK delivery for Holoai: translating product requirements and supplied designs into an integration architecture, implementing and packaging the SDK, planning releases, and resolving issues throughout integration.

I was the direct technical counterpart for Zürich Tourism and Binarium. That meant defining the interface between the SDK and the native host apps, documenting integration requirements, coordinating changes across teams, and carrying the work through four delivery milestones.

What I delivered

• The AI guide: chat with voice input; inline map links and follow-up questions; narrated points of interest
• Native feature integration: open recommendations on the map and save favorite places through a defined host-app interface
• A plug-and-play SDK: XCFramework via Swift Package Manager and AAR via Maven, consumed like a native dependency
• Showcase apps reproducing the relevant Zürich app flows so the complete integration could be developed and tested independently
• Error and crash monitoring, opt-in analytics, clear integration & developer guides.
• Iterative releases: automated CI and changelogs.

Results

• Live since 2026 in the Zürich City Guide app with 100K+ downloads (App Store and Play Store).
• Delivered a reusable brownfield SDK architecture for future integrations into existing native apps.

Screenshots