Senior Android Developer
& Software Architect

January 2025 – Present

Software Engineer at firecoder GmbH, engaged by RTL Deutschland. Architecture, development, and consulting for the RTL Android Streaming SDK.

I continue to evolve the RTL Android Streaming SDK that powers video playback across the corporation’s apps, including RTL+ (10M+ installs on Google Play), ntv (5M+), Super RTL Toggo (5M+), Stern (1M+), and Wetter. I drive its integration into these products and work closely with the product teams and stakeholders on new features and extensions.

The SDK covers DASH and CMAF adaptive streaming, live and on-demand playback with low latency, Widevine DRM (L1/L3) and PlayReady, offline downloads with persistent DRM licenses, server-side and client-side ad insertion including non-linear ads, subtitles, multiple audio tracks, accessibility, and Android TV support. Playback and audience measurement are integrated via Nielsen, AGF, Google Analytics, and NPAW.

As a library consumed by several app teams, the SDK is built as a Gradle multi-module project with a focus on public API design, semantic versioning, backward compatibility, and migration guides. I write the developer documentation and support the integrating app teams, and I established a multi-level test strategy, including setting up and running a Marathon device farm for automated on-device testing.

April 2023 – December 2024

RTL+ Android Mobile, Fire TV, and TV App. Architecture, development, and consulting.

Alongside the RTL+ apps, I evolved the RTL Android Streaming SDK that powers video playback across the corporation’s apps, including RTL+ (10M+ installs on Google Play), ntv (5M+), Super RTL Toggo (5M+), Stern (1M+), and Wetter. I drove its integration into these products and worked closely with the product teams and stakeholders on new features and extensions.

The SDK covers DASH and CMAF adaptive streaming, live and on-demand playback with low latency, Widevine DRM (L1/L3) and PlayReady, offline downloads with persistent DRM licenses, server-side and client-side ad insertion including non-linear ads, subtitles, multiple audio tracks, accessibility, and Android TV support. Playback and audience measurement are integrated via Nielsen, AGF, Google Analytics, and NPAW.

As a library consumed by several app teams, the SDK is built as a Gradle multi-module project with a focus on public API design, semantic versioning, backward compatibility, and migration guides. I wrote the developer documentation, supported the integrating app teams, and established a multi-level test strategy.

October 2022 – May 2023

Android app of BARMER, one of Germany’s largest statutory health insurers. Architecture, development, and consulting via T-Systems as general contractor.

As the sole Android developer, I designed and built the digital vaccination record (Digitaler Impfpass) from scratch as a new module of the BARMER app. I made all architecture decisions for the module, presented them to T-Systems for approval, and implemented the feature end to end against a REST backend while handling sensitive health data under GDPR requirements.

I set up the project foundation: a modular structure with Clean Architecture and MVVM, Jetpack Compose from day one, a test strategy covering unit and Android UI tests, and the TeamCity CI/CD pipeline with automated tests, Android Lint, ktlint, and detekt.

March 2021 – October 2022

RTL+ Android Mobile, Fire TV, and TV App. Architecture, development, and consulting.

Alongside the RTL+ apps, I evolved the RTL Android Streaming SDK that powers video playback across the corporation’s apps, including RTL+ (10M+ installs on Google Play), ntv (5M+), Super RTL Toggo (5M+), Stern (1M+), and Wetter. I drove its integration into these products and worked closely with the product teams and stakeholders on new features and extensions.

The SDK covers DASH and CMAF adaptive streaming, live and on-demand playback with low latency, Widevine DRM (L1/L3) and PlayReady, offline downloads with persistent DRM licenses, server-side and client-side ad insertion including non-linear ads, subtitles, multiple audio tracks, accessibility, and Android TV support. Playback and audience measurement are integrated via Nielsen, AGF, Google Analytics, and NPAW.

As a library consumed by several app teams, the SDK is built as a Gradle multi-module project with a focus on public API design, semantic versioning, backward compatibility, and migration guides. I wrote the developer documentation, supported the integrating app teams, and established a multi-level test strategy.

July 2022 – December 2022

Conception, architecture, and development of a SaaS web application that lets 3D artists generate textures with generative AI.

As co-founder and managing director, I was technically responsible for the platform and led the team on the backend and app side, while a co-founder owned the AI model. I designed the architecture: a React frontend in TypeScript, a serverless AWS backend written in Rust on Lambda with DynamoDB and Cognito, and an event-driven generation pipeline where SQS decouples user requests from Docker-based workers on EC2.

The infrastructure is defined as code with AWS CDK and delivered through GitHub and Bitrise CI. We validated the concept with a working prototype and made the deliberate decision to discontinue the product after three months rather than scale it.

January 2019 – July 2022

A mobile app for Android and iOS to track staff during emergency operations and manage fire brigade organizations, published on Google Play. My own fire brigade has been using AlarmBoard in active service since 2019.

I owned the full architecture for both the app and the serverless AWS backend, and guided my co-founders through the development process. The backend runs on API Gateway, Lambda, DynamoDB, and Cognito, with a REST API and WebSockets for live operation status. The app is fully offline-capable with background sync, and all personal data is encrypted on the device so that only the user can access it in their own app, in line with GDPR.

The app’s layered clean architecture allowed us to migrate from native Kotlin to 100% Dart/Flutter in mid-2020 by swapping individual layers, without a full rewrite, and brought iOS to the product in the process. Infrastructure is defined as code with AWS CDK and delivered through Bitrise CI.

Funded as an innovative startup by the Federal Ministry for Economic Affairs and Climate Action of Germany, which enabled us to exhibit at INTERSCHUTZ 2022, the world’s leading trade fair for fire prevention, rescue, and safety. Awarded the Startup Award 2022.

Flutter Dart Kotlin RxKotlin / RxDart Clean Architecture Android Architecture Components Offline-First On-Device Encryption GDPR AWS Serverless API Gateway REST WebSockets Lambda DynamoDB Cognito EC2 AWS CDK Bitrise CI Google Play

August 2017 – March 2021

Germany’s electronic health record (“elektronische Gesundheitsakte” / eGA) and electronic patient record (“elektronische Patientenakte” / ePA), delivered by IBM both as a white-label Android app and as an SDK that health insurers integrate into their own apps.

As Subject Matter Expert for Android, I designed and developed core components of the eGA and ePA Android apps within a multi-team context. My responsibilities included architectural design, native Android development, and conducting client-facing presentations and workshops. I facilitated the integrations for five health insurers (Techniker Krankenkasse, BARMER, HEK, VIACTIV, and Knappschaft-Bahn-See) and served as the primary contact for a major private health insurer.

Health data is encrypted on the device, and authentication runs via OpenID Connect with Keycloak. To let insurers embed the eGA into their existing apps, I built a Capacitor wrapper module around the native Android SDK. Quality was secured by unit, integration, and UI tests running in a Jenkins CI/CD pipeline.

January 2017 – June 2017

iOS SDK for Germany’s standardized medication plan (“Bundeseinheitlicher Medikationsplan”), letting health insurers integrate medication plan management into their own apps.

I extended the SDK and the reference app built on it, which was integrated into several insurer apps.

January 2016 – December 2016

I developed middleware, client application, and database components for a grid operator management system in the energy sector. In a Scrum team, I built both the Angular 2 frontend and the Java/Spring backend, backed by an Oracle SQL database.

January 2016 – December 2016

In a small team, I developed an SAP UI5 application.

October 2015 – December 2016

Further development, maintenance, and support of existing Android and iOS apps. Development of app prototypes.