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# (Senior) Mobile Engineer - iOS & Android

- **Company:** Paymenttools
- **Location:** Köln, Germany
- **Experience:** Expert
- **Contract:** Permanent contract
- **Skills:** LTE (Telecommunication), Application Programming Interfaces (APIs), Agile Methodology, Android Software Development, IOS Applications, Asana, Confluence, JIRA, Mobile Application Development, Payment Systems, Mobile Application Software, Release Management, Management of Software Versions, Ios Frameworks, Kotlin, Slack, Gsuite, Api Design, Interactive Whiteboards
- **Published:** October 6, 2026
- **Apply:** https://www.indeed.com/viewjob?jk=79be3f529c1bdec7

## About the Role

* Several years of professional mobile engineering experience, with extensive native iOS development expertise
 * Deep knowledge of the Apple ecosystem and modern iOS development, ideally including Swift and commonly used iOS frameworks and architectural approaches
 * Practical experience developing Android applications or libraries with Kotlin, and the ability and willingness to work across both platforms when needed
 * Experience building or maintaining SDKs, libraries, frameworks, or other developer-facing platform components
 * Strong understanding of public API design, semantic versioning, backwards compatibility, deprecation strategies, and release management
 * A solid architecture and product mindset-you think beyond individual tickets and consider maintainability, integration experience, and long-term evolution
 * Fluent English, German skills are a plus
 * Experience with payment technologies, SoftPOS, security-sensitive mobile applications, or regulated environments is a strong advantage-but not required

## Description

* Own, develop, and evolve the iOS implementation of our WhiteLabelPay SDK and future iOS applications.
 * Design stable, intuitive, and developer-friendly public APIs that are easy for customers to integrate and difficult to misuse.
 * Work across iOS and Android to ensure consistent behaviour, concepts, states, errors, and integration contracts between platforms.
 * Contribute to Android development and architecture using Kotlin, collaborating closely with Android engineers while bringing strong cross-platform awareness.
 * Improve the overall developer experience through high-quality documentation, sample applications, integration guidance, and tooling.
 * Build and maintain mobile products beyond the SDK, including payment applications and components connecting mobile or IoT devices with our payment platform.
 * Collaborate closely with product, engineering, architecture, customers, and other stakeholders to turn complex payment requirements into simple and reliable mobile interfaces., * Flexible working hours that fit your workflow, your time matters
 * Language courses (English and German)
 * Responsibility from day one
 * Work with modern and agile software such as Google Workspace, Slack, Asana, Jira, Lattice, Miro and Confluence
 * Company events including Hackathons and Company Days
 * Ask us more about these!