Stephan Schulz

My core expertise lies in building scalable mobile applications using native iOS and Flutter. With 20+ years’ experience, I bring a holistic approach that helps teams move forward with clarity and purpose. I create structure in complex environments, think long-term, support products through steady execution, mentor thoughtfully, and foster positive, collaborative teams.

At On, I was an integral part of building their first public multilingual iOS/Android app using Flutter. I contributed to key features like Product List, Search, Product Detail, Cart, and Checkout. The app used layered architecture with BLoC for state management, GetIt/Injectable for dependency injection, and AutoRoute for navigation. Modular UI components improved consistency, with full unit and snapshot test coverage. I also helped implement a cross-platform payment plugin. The project followed Scrum.

At Vivy, a digital healthcare assistant, I researched, designed, and implemented a Server Driven UI (SDUI) in Swift. The solution used a modular design system with reusable components as building blocks for dynamic screen layouts. A node-based builder tool allowed insurers to create interactive user flows like questionnaires to assess health habits. Additionally, I supported the hiring process by preparing, reviewing, and conducting candidate interviews.

At On, a Swiss sportswear brand, I supported the setup of their Berlin IT team by defining workflows, documenting infrastructure, aiding in hiring, and improving native Swift apps. I introduced Flutter after evaluating cross-platform tools, leading to a full rewrite of their catalog app. Built with MVVM and Redux, the multilingual app featured full test coverage with unit and snapshot tests, streamlining future development and ensuring cross-platform consistency.

Joined Durstexpress, a last-mile beverage delivery service, early in the iOS app’s development and contributed from first implementation to release. The app used VIP architecture with modular, reusable components in frameworks. CI/CD ran via Bitrise. Screens were built with UICollectionView using reusable cells and view models, following an atomic design system. The project included unit and snapshot tests to ensure stability and consistency.

The SalonLab Smart Analyzer is the first device that enables hairdressers to scan a client’s hair structure using near-infrared technology. The device communicates via Bluetooth with an iPad app that visualizes both the scanning process and results. I joined the iOS team to help complete the app on time, focusing on rapidly adapting the existing architecture and infrastructure to support new features, reviewing merge requests, and optimizing overall performance.

Led the architectural design and CI infrastructure setup for a large-scale banking application. The goal was to establish a solid foundation for a next-generation platform that supports traditional banking features—such as account management and transaction execution—while also serving as a digital currency wallet. My responsibilities included setting up the entire continuous integration and delivery pipeline, along with comprehensive documentation of all aspects of the project.

Performed stability and performance updates for a legacy Salesforce application, focusing on log and crash report analysis to restore compatibility and stability with the latest iOS version. Utilized a range of profiling tools to identify and resolve memory and threading issues.

Developed several new features for a road-based recommendation app, with a focus on implementing a map view that uses clustering to efficiently display large volumes of data. Also contributed to integrating community-driven features within the user profile.

As Lead Developer, I built Mercedes AMG AR, a suite of two ARKit 2-based apps for 3D object detection. The first app scanned physical objects and managed scan data; the second used those scans to recognize real-world objects and overlay detailed 3D models in AR. Key challenges included realistic rendering of the AMG engine, minimizing ARKit glitches, and ensuring stable, high-quality AR sessions.

As Lead Developer, I built the Mercedes me media iOS app from the ground up and maintained it for several years. It offered access to brand news, media assets, and personalized content for events and presentations. The architecture followed MVVM using ReSwift and ReactiveSwift, with a declarative routing engine for navigation and deep linking. Due to strict security policies, the app included code obfuscation and encryption to protect user data and prevent misuse.

Development of a custom Cordova camera plugin for iOS.

Led development of a mobility and safety prototype for a German automotive manufacturer.

Development of a shopping app with similar features to Instagram (Stream, Camera, Profile) in Swift. The chosen architecture was MVVM with Data Binding and Coordinator pattern. Continuous Integration with Travis. UI testing with Google’s Earl Grey.

Led the development of a music streaming app prototype in Swift, similar to Spotify, with a focus on offline caching and leveraging AVFoundation for a seamless listening experience.

Developed several new MapKit-related features and contributed to architectural improvements of a car-sharing app. The project followed agile practices, including pair programming, timeboxing, Scrum, and thorough code reviews.

What Drops Now is an affiliate platform by Highsnobiety, designed to help users discover tomorrow’s trends more easily. I led the development of the iPhone and iPad app, which was also my first project using Swift.

Led development of an interactive macOS app for a smart mirror, controlled via a Bluetooth-enabled toothbrush and face tracking. The application was showcased at Mobile World Congress 2015.

Developed interactive components of the ARAG consultation app for iPad, including animations and visualizations of various insurance topics.

Led the development of a range of touchscreen applications for Deutsche Telekom trade show presentations at events like CeBIT and IFA. This included a Backbone.js-powered HTML5 app published on the App Store. Most applications were built with Adobe AIR to enable hardware-accelerated, fullscreen, cross-platform experiences.