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Lennart WisbarLW

Lennart Wisbar

iOS Developer

€680/day
Neumünster, DE
3-7 years
Swift
iOS
SwiftUI
Git
TDD

Average response time: 1 hour

About Lennart

Passionate iOS developer with 4 years of professional experience (+12 years as a hobby), based in northern Germany. Strong focus on high-quality, scalable software design and fast, reliable unit tests. Enjoys learning, growing, and sharing knowledge.

Currently working part-time with limited but reliable availability (up to 15 hours per week).

Personal side project on the App Store for iPhone and iPad, as well as open-source on GitHub: TrackChart (SwiftUI Charts, SwiftData, iCloud, localization in English and German, CI/CD with GitHub Actions and Xcode Cloud, TestFlight).

Community moderator at Essential Developer Academy.

Blog: swiftforpirates.com
Film and audiovisual (AV)

  • German

    Native or bilingual

  • English

    Fluent

Can work on-site
Neumünster (up to 50km)

Experience

  • RTL Technology
    iOS Developer (Intermediate)
    ENTERTAINMENT AND LEISURE
    July 2024 - February 2026 (1 year and 7 months)
    Köln, Germany
    • Continued development of the RTL+ app (>6 million paying users), initially in the Live Events team (SwiftUI, MVVM, async/await, Apollo GraphQL SDK).
    • Took part in collaborative software design decisions.
    • Applied new knowledge from the training course (see below), such as: Introducing unit tests for memory leaks. Reducing test duration in the Live Event target from 40s to 0.5s, enabling TDD workflows.
    • After team consolidation, contributed across all parts of the RTL+ app (VoD, live events, live TV, music, audiobooks, podcasts, magazines – UIKit and SwiftUI).
    • Designed clean solutions for platform-specific conditions during the app's tvOS expansion.
    • Regularly built release candidates and monitored analytics metrics (BugSnag, Grafana) in the "Greenkeeper" role.
    iOS SwiftUI Mobile App Deployment TDD Git
  • RTL Technology
    iOS Developer (Junior)
    ENTERTAINMENT AND LEISURE
    January 2022 - June 2024 (2 years and 5 months)
    Köln, Germany
    • Developed the RTL+ app as part of the VoD team (UIKit, Clean Swift, Combine).
    • Gained experience with agile methodologies (Scrum, SAFe).
    • Grateful to have turned my long-time hobby into a career, with daily learning through pair programming and valuable code reviews.
    • Built the new live events section of the app in SwiftUI as part of a cross-functional team. With only three iOS developers involved, I gained broader responsibility and direct influence on software design.
    • Assisted in delivering a standalone music app on time as part of a special assignment.
    • Shadowed the Core team to contribute to the CI pipeline (Fastlane, Docker, GitLab).
    iOS SwiftUI UIKit CI/CD Management Git

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Education

  • iOS Lead Essentials
    Essential Developer Academy
    2024
    iOS Lead Essentials

Certifications

Skill set

Design Patterns
Mobile App Deployment
Software Architecture
CI/CD Management

Categories