Senior iOS Engineer – Identity & Security (REF5703H)

As Hungary’s most attractive employer in 2025 (according to Randstad’s representative survey), Deutsche Telekom IT Solutions is a subsidiary of the Deutsche Telekom Group. The company provides a wide portfolio of IT and telecommunications services with more than 5300 employees. We have hundreds of large customers, corporations in Germany and in other European countries. DT-ITS recieved the Best in Educational Cooperation award from HIPA in 2019, acknowledged as the Most Ethical Multinational Company in 2019. The company continuously develops its four sites in Budapest, Debrecen, Pécs and Szeged and is looking for skilled IT professionals to join its team. Join us in building Germany’s next-generation Identity Provider for the national healthcare Telematics Infrastructure (TI), enabling millions of statutory health insurance members to securely access digital healthcare services. You will work on a security-critical, gematik-regulated platform focused on production-grade identity and access management, OAuth 2.0/OpenID Connect (OIDC), hardware-backed cryptography, personal data protection, and audit-grade software quality. The platform consists of a modern Java 25 / Spring Boot 4.1 backend and a cross-platform mobile identity SDK used by multiple healthcare applications. As a Senior iOS Engineer, you will own the iOS side of the identity SDK, developing secure authentication journeys in Swift and SwiftUI , implementing Secure Enclave–backed cryptographic operations, and delivering XCFramework packages consumed by applications from leading German statutory health insurers. If you also have experience with Kotlin Multiplatform (KMP), you will have the opportunity to contribute to the shared cross-platform mobile architecture and help shape the future of the identity platform across iOS and Android. Key Responsibilities Design, develop, and maintain the iOS components of a security-critical identity SDK using Swift 5.x and SwiftUI Implement secure OAuth 2.0 and OpenID Connect (OIDC) authentication and authorization flows for healthcare identity services Develop and maintain secure key management solutions using Secure Enclave and Keychain Protect authentication tokens, cryptographic material, and sensitive personal data according to industry best practices Integrate eID-based identification workflows (e.g., AusweisApp2) into the mobile SDK Build, package, and distribute SDK releases as XCFrameworks for external application teams Own release management processes, including code signing, certificate management, and distribution using Fastlane Match, TestFlight, and App Store Connect Develop and maintain comprehensive unit, integration, and automated tests using XCTest Collaborate closely with backend, security, and Kotlin Multiplatform engineering teams Participate in architecture discussions, code reviews, technical documentation, and continuous improvement initiatives Ensure compliance with security, regulatory, and quality requirements in a highly regulated healthcare environment 5+ years of professional experience in iOS software development Strong expertise in Swift 5.x and Swift UI Hands-on experience building and distributing reusable frameworks or SDKs, including XCFrameworks Proven experience implementing secure mobile authentication solutions using OAuth 2.0 and OIDC Practical knowledge of Secure Enclave, Keychain, and iOS cryptographic APIs Experience with XCTest, automated testing, and CI/CD pipelines Strong understanding of iOS release processes, code signing, and certificate management Experience using Fastlane, TestFlight, App Store Connect, and Git-based workflows Strong communication skills and experience working in cross-functional Agile teams Fluent English, both written and spoken Advantages: Experience with Kotlin 2.x and Kotlin Multiplatform (KMP) Knowledge of KMP-Swift interoperability and shared mobile architecture Experience integrating AusweisApp2 or similar Eid solutions Familiarity with device attestation, application integrity, and mobile security frameworks Experience working in healthcare, digital identity, fintech, or other regulated industries Understanding of German healthcare infrastructure, including gematik, eGK, and digital identity ecosystems Relevant security certifications are a plus Technology Stack Core Technologies Swift 5.x SwiftUI XCTest XCFramework Secure Enclave Keychain Services OAuth 2.0 OpenID Connect (OIDC) DevOps & Delivery Fastlane (Match, Code Signing) TestFlight App Store Connect CI/CD Pipelines Git What We Offer The opportunity to help build one of Germany’s most important healthcare identity platforms A modern engineering environment with an ADR-driven architecture culture Work on security-critical systems that impact millions of citizens Collaboration with highly skilled engineers specializing in identity, security, and mobile technologies Professional development opportunities in mobile security, digital identity, and cross-platform engineering A culture of quality, ownership, and continuous learning Flexible and collaborative working environment * Please be informed that our remote working possibility is only available within Hungary due to European taxation regulation.