Freelance Mobile Developer

• Developed the SecureMessaging Android and iOS app (authorization medium) to approve transactions in M.M.Warburg Bank's online banking.
• Developed a high-performance trading app for iOS and Android.
• Designed the architecture for scalable white-label apps on iOS and Android for banks and financial institutions.
• Updated outdated libraries and modernized the codebase of existing apps.
• Migrated from XML to Jetpack Compose (Android) and from Xib/Storyboards to SwiftUI (iOS).
• Provided security consulting and implemented CI pipelines to optimize workflows.

• Developed the Moovility and EVN apps for charging electric cars on iOS and Android, including CarPlay and Android Auto integration.
• Designed the system architecture for payment modules and end-to-end testing.
• Optimized the payment API for mobile applications with a focus on security.

• Developed various iOS apps (e.g., HNGRY, Components, Smart Device 2.0).
• Introduced modern app architectures with SwiftUI, Combine, and async/await.
• Mentored and trained junior developers and conducted tech talks.

• Designed and developed a custom Order Management System (OMS) from scratch, including a REST API, iOS and Android apps, and a web-based admin tool.
• Implemented a tailored OMS to optimize order processing and inventory management across multiple platforms.
• Helped the client digitize the order flow, moving from email-based processes to a more efficient, integrated system.
• Developed and integrated the apps and web-based admin tool with the OMS API for seamless operation.
• Advised the client on security, digital transformation, and process optimization to increase efficiency in sales and distribution.

• Served as Lead App Developer and architect for the internal ticket system S5.
• Developed REST APIs with PHP Symfony 3 and implemented features for iOS and Android apps.
• Took on the role of interim Scrum Master to foster agile processes and team coordination.
• Created an iOS App Prototyping Kit to streamline app development.
• Mentored the winning team in the MS Business Hackathon 2017 and supported other app developers.
• Trained and guided junior developers.

Lead Mobile Developer (DriveNow, 2015):

• Managed project and release cycles for the DriveNow iOS app.
• Maintained and enhanced the DriveNow Windows Phone app.
• Implemented the DriveNow Apple Watch app.

Lead iOS Developer (myDriver, 2014):

• Managed project and release cycles for the myDriver iOS app.
• Designed RESTful APIs and managed CI/CD pipelines with Jenkins.
• Collaborated with and supported external developers for seamless integration and consistency.

iOS Developer (2013):

• Developed and maintained various iOS apps, including iSixt, Sixt Mobility for BMW, and Sixt Leasing.
• Worked on iBeacon projects (iOS MVPs) and an indoor navigation app for airport parking garages.
• Implemented location-based ad features for the iSixt app.