Hi, I’m Sebastian Volling, a seasoned iOS engineer with 12+ years of experience shipping mobile apps and integrating SDKs across Apple and Android platforms. I have deep expertise in Swift, SwiftUI, and the iOS ecosystem, with hands-on experience in Kotlin/Android and cross‑platform development. I’ve led small remote teams, improved developer experience through architecture refactors, and delivered production code to the App Store and Google Play. I’m comfortable working across the full stack—from native mobile SDKs to server‑side Swift (Vapor) and Kotlin Spring Boot APIs—and I enjoy collaborating with stakeholders to design robust, scalable mobile solutions.…

Sebastian Volling

Hi, I’m Sebastian Volling, a seasoned iOS engineer with 12+ years of experience shipping mobile apps and integrating SDKs across Apple and Android platforms. I have deep expertise in Swift, SwiftUI, and the iOS ecosystem, with hands-on experience in Kotlin/Android and cross‑platform development. I’ve led small remote teams, improved developer experience through architecture refactors, and delivered production code to the App Store and Google Play. I’m comfortable working across the full stack—from native mobile SDKs to server‑side Swift (Vapor) and Kotlin Spring Boot APIs—and I enjoy collaborating with stakeholders to design robust, scalable mobile solutions.…

Available to hire

Hi, I’m Sebastian Volling, a seasoned iOS engineer with 12+ years of experience shipping mobile apps and integrating SDKs across Apple and Android platforms. I have deep expertise in Swift, SwiftUI, and the iOS ecosystem, with hands-on experience in Kotlin/Android and cross‑platform development.

I’ve led small remote teams, improved developer experience through architecture refactors, and delivered production code to the App Store and Google Play. I’m comfortable working across the full stack—from native mobile SDKs to server‑side Swift (Vapor) and Kotlin Spring Boot APIs—and I enjoy collaborating with stakeholders to design robust, scalable mobile solutions.

See more

Skills

Experience Level

iOS
Expert
Swift
Expert
Kotlin
Expert
Docker
Expert
GraphQL
Expert
MariaDB
Intermediate
AWS
Intermediate
Azure
Intermediate
MongoDB
Intermediate

Language

German
Fluent
English
Fluent

Work Experience

Lead iOS Developer at IU International University of Applied Sciences
May 1, 2025 - September 18, 2025
Led a team with up to 4 other iOS developers; enhanced the application's features to effectively fix bugs and optimize overall performance, reliability, and efficiency; set up and configured a local Swift web server within the application to provide full access to the hybrid content parts of the app; supported the PO in feature development and technical exchange with stakeholders.
iOS Developer (Freelance) at Jamitlabs
February 1, 2025 - December 1, 2025
Integrated RoomPlan SDK for room scanning and 2D floor plan generation across the PasKal, DocuSketch, and InstantFloorplan apps. Introduced Swift Concurrency to parallelize network calls, database operations, and background sync, improving app responsiveness. Refactored core architecture from TCA to MVVM, improving maintainability and developer experience for the team. Main communication bridge between client and external developers, ensuring clear requirement alignment.
Freelance iOS Developer at Jamitlabs
February 1, 2025 - Present
Contributes to the iOS apps PasKal and DocuSketch; acts as the main communication bridge between the client and external developers to align requirements and ensure smooth technical collaboration; improved app performance by introducing Swift Concurrency to parallelize network calls, database operations, and background sync logic; refactored core architecture by transitioning from The Composable Architecture (TCA) to MVVM to improve maintainability and development efficiency.
Lead iOS Developer at IU International University of Applied Sciences
April 1, 2022 - May 1, 2025
Led a team of up to 4 iOS developers, coordinating feature development and code reviews. Set up a local Swift web server within the app for hybrid content delivery. Improved performance, reliability, and efficiency across the iOS application. Technical exchange with stakeholders and PO on feature development and roadmap.
IT Consultant at Lufthansa Industry Solutions
March 1, 2022 - September 18, 2025
Contributed to multiple projects including Hermes (Kotlin Spring Boot API, Kotlin Android, TypeScript Frontend, AWS, Terraform, Jenkins); LHT (Lufthansa Technik): Aviatar (Kolin - Spring Boot API, MSSQL, Openshift, Azure, Jenkins); LH Cargo: LAT Flashcards (Cross-platform app, iOS & Android, Xamarin C#), CheckIn App (iOS App Swift), Linde: Installation App (iOS App Swift), LHIND: Presence App (iOS App Swift, Kolin Spring Boot API), Push-Service (Java Spring Boot API, Azure, MariaDB, Docker).
IT Consultant at Lufthansa Industry Solutions
September 1, 2018 - March 1, 2022
Hermes: Last Mile Application -- Kotlin Spring Boot API, Kotlin Android App, TypeScript Frontend, AWS, Terraform. LHT: Aviatar -- Kotlin Spring Boot API, MSSQL, OpenShift, Azure. LH Cargo: LAT Flashcards -- Cross-platform app (iOS & Android, Xamarin C#), CheckIn app (iOS, Swift). LHIND: Presence App -- iOS app (Swift), Kotlin Spring Boot API, Push-Service (Java Spring Boot, Azure, MariaDB, Docker).
Senior iOS Developer at GovConnect GmbH
August 1, 2018 - September 18, 2025
iOS development responsibilities across multiple client projects, contributing to feature development, code reviews, and performance optimizations.
Senior iOS Developer at GovConnect GmbH
December 1, 2015 - August 1, 2018
Led a two-person development team. Built pmOWI app for digital parking space monitoring (Objective-C & Swift). Built a Xamarin C# app delivering identical features across Android and Windows Mobile.
iOS Developer at Teamplace GmbH
November 1, 2015 - September 18, 2025
iOS development contributions for Teamplace products, focusing on delivering stable features and improved user experience.
iOS Developer at expectare GmbH
December 1, 2014 - September 18, 2025
iOS development duties within the expectare team, implementing features and maintaining app quality.
iOS Developer at expectare Deutschland GmbH
May 1, 2014 - December 1, 2014
iOS development role.
iOS Developer at datedicted GmbH
April 1, 2014 - September 18, 2025
iOS development responsibilities in the Berlin office, contributing to app development and maintenance.
iOS Developer at datedicted GmbH
April 1, 2013 - May 1, 2014
iOS development role.

Education

IT Specialist for Application Development (IHK) at GPB - Society for Personnel Development and Education (Berlin)
February 1, 2012 - February 1, 2014
Project Management at Education center at the IFW (Jena)
February 1, 2009 - February 1, 2009
Quality Management at GBW non-profit vocational training center (Münster)
February 1, 2009 - February 1, 2009
IT Specialist (Fachinformatiker Anwendungsentwicklung), IHK-certified at GBP Neukolln
January 1, 2012 - January 1, 2014

Qualifications

IT Specialist for Application Development (IHK)
February 1, 2012 - February 1, 2014
Project Management
February 1, 2009 - February 1, 2009
Quality Management
February 1, 2009 - February 1, 2009
IHK-certified Fachinformatiker Anwendungsentwicklung
January 1, 2012 - January 1, 2014

Industry Experience

Government, Healthcare, Education, Travel & Hospitality, Software & Internet, Computers & Electronics, Professional Services, Media & Entertainment
    DiceTales - Stories through dice and AI

    DiceTales — Stories Through Dice and AI

    An AI-powered storytelling app where dice rolls shape the narrative. Part
    game, part creative writing tool, entirely unique.

    The Idea

    What happens when you combine the randomness of tabletop dice with generative
    AI? DiceTales turns every roll into a story beat — characters react, plots
    twist, and no two sessions play out the same way. It’s collaborative
    storytelling between you and AI, guided by chance.

    What I Built

    • Native iOS app in Swift and SwiftUI
    • AI narrative engine generating contextual, branching storylines from dice
      outcomes
    • Firebase Cloud Functions as a secure proxy layer — API keys never touch
      the client, rate limiting enforced server-side
    • Dice mechanics that map physical game concepts (skill checks, critical hits,
      fumbles) to narrative events

    Architecture Highlight

    Security was a first-class concern. Instead of embedding API keys in the app
    binary (a common shortcut), I built a Firebase Cloud Functions layer that acts
    as a secure intermediary. The client authenticates, the function validates
    and rate-limits, then proxies the request. Zero secrets on-device.

    Why It Matters

    DiceTales shipped to the App Store in 2023 — before the current wave of
    AI-powered apps. It demonstrates early, production-grade experience with LLM
    integration in a native mobile context, wrapped in a creative concept that
    makes the technology feel playful rather than intimidating.

    **Live on the App Store —
    [Dice Tales](https://www.twine.net/signin

    Markr - Save places

    Markr — Save Places

    A focused, single-purpose iOS app for saving and organizing locations that
    matter to you.

    The Idea

    Some apps try to do everything. Markr does one thing well: letting you save
    places and find them again when you need them. No account required, no cloud
    sync, no bloat — just your places, stored locally on your device.

    What I Built

    • Native iOS app built entirely in Swift and SwiftUI
    • On-device persistence with local data storage — your data stays on your
      phone
    • Clean, minimal UI designed around speed: save a place in under 3 seconds
    • Map integration for visual browsing of saved locations

    Why It Matters

    Markr is a deliberate exercise in restraint. In a landscape of feature-bloated
    apps, I wanted to prove that a well-scoped, well-executed utility still has a
    place. Ship fast, ship lean, solve one problem completely.

    **Live on the App Store —
    [Markr - Save places](https://www.twine.net/signin

    Evanthium

    Evanthium

    A location-based AR game with blockchain integration — designed, built, and
    shipped solo across iOS, Android, and a server-side Swift backend.

    The Idea

    Evanthium blends the physical and digital world: players explore real
    locations, interact with AR elements, and earn crypto tokens through gameplay.
    Think geocaching meets augmented reality, with a blockchain reward layer on
    top.

    What I Built

    This is a full-stack solo project — I own every layer:

    • iOS app: Swift, SwiftUI, ARKit for augmented reality experiences
    • Android app: Kotlin, bringing feature parity to a second platform
    • Backend: Server-side Swift with Vapor, handling real-time game
      state, player interactions, and spatial data processing
    • Real-time communication: WebSockets for live multiplayer updates
    • Blockchain integration: Crypto token rewards tied to in-game
      achievements via blockchain APIs
    • Infrastructure: Full deployment pipeline from API design to production

    Architecture Highlight

    The entire backend runs on server-side Swift (Vapor) — the same language as
    the iOS client. This isn’t a common choice, but it pays off: shared models,
    shared logic, and a single language across the stack. Real-time location data
    flows through WebSockets, processed server-side for game logic, then pushed
    back to connected clients.

    Why It Matters

    Evanthium is proof that one engineer can ship a production-quality,
    multi-platform product — from database schema to App Store review. It combines
    five non-trivial domains (AR, real-time networking, blockchain, iOS, Android)
    into a coherent product that real users can download today.

    **Live on the App Store and Google Play —
    [evanthium.com](https://www.twine.net/signin