freiberufler Senior Software Developer (Android, Kotlin, Ktor, gen. AI / KI / GPT) auf freelance.de

Senior Software Developer (Android, Kotlin, Ktor, gen. AI / KI / GPT)

zuletzt online vor 1 Tagen
  • auf Anfrage
  • Bad Bramstedt
  • DACH-Region
  • de  |  en
  • 26.06.2025

Kurzvorstellung

I'm a senior Android developer with 10+ years of experience — now blending native app expertise with cutting-edge generative AI. From Kotlin and Jetpack Compose to OpenAI and Flux, I build modern, scalable, AI-powered apps from idea to deployment.

Auszug Referenzen (1)

"Freelancer in own company"
Android Developer (Freelancer)
Tobias Boehm
Tätigkeitszeitraum

1/2012 – 1/2017

Tätigkeitsbeschreibung

Freelancing as an Android developer working with Random House GmbH as well as in-house apps for Siemens and other start-ups.

Eingesetzte Qualifikationen

Android Entwicklung, Java (allg.), Mobile Application Development, CSS (Cascading Style Sheet), HTML

Qualifikationen

  • Android5 J.
  • Android Developer
  • Android Entwicklung8 J.
  • Backend2 J.
  • Dependency Injection
  • Git2 J.
  • Google Cloud2 J.
  • Graphql1 J.
  • Jetpack Compose
  • Jira3 J.
  • Junit
  • Kotlin9 J.
  • Material Design
  • Mobile Application Development7 J.
  • Reactive Programming
  • Scrum3 J.

Projekt‐ & Berufserfahrung

Freelance Senior Android Developer
IBM, Hamburg
10/2024 – offen (10 Monate)
IT & Entwicklung
Tätigkeitszeitraum

10/2024 – offen

Tätigkeitsbeschreibung

Together with the existing team for the electronic patient record (ePA), I maintained the Android white-label solution of the ePA v3.0 and v3.0.5 and added new features.

Android, Kotlin, Compose, Coroutines, Kotlin Multiplatform (KMP), MVI, MVVM, Teams, Confluence, Jira

Eingesetzte Qualifikationen

Android Developer, Kotlin

Freelance Senior Android Developer
Blueworld GmbH, Köln
1/2024 – 9/2024 (9 Monate)
Versorgungswirtschaft
Tätigkeitszeitraum

1/2024 – 9/2024

Tätigkeitsbeschreibung

Zusammen mit dem existierenden Android Team habe ich Teile der Tracemate Android App architektonisch und strukturell generalüberholt (Einführung von Clean Code & Clean Architecture), sowie existierende Prozesse verbessert.

Tools und Skills: Clean Code, Clean Architecture, Coroutines, RXJava, Kotlin, Model View Intent, Dagger2/Hilt, SCRUM, Mockk, Slack, Confluence, Jira

Eingesetzte Qualifikationen

Confluence, Scrum, Android Entwicklung, Reactive Programming, Git, Jira

Senior Android Developer
Congstar, Köln
9/2023 – 1/2024 (5 Monate)
Telekommunikation
Tätigkeitszeitraum

9/2023 – 1/2024

Tätigkeitsbeschreibung

Together with the team of Congstar I helped to modularize the main app and introduce code quality controls (think clean architecture and modularization by functionality + ktlint and detekt). All new UI components were implemented with Compose.

Tools and Skills: Kotlin, Dependency Injection, Coroutines, MVI, Retrofit/okhttp, GitLab, AndroidX, Mockk, Espresso, Jetpack Compose, detekt, ktlint, Scrum / Kanban, Confluence, Jira, MS Teams

Eingesetzte Qualifikationen

Android, Java (allg.), Kotlin

Mobile- & Backend Developer of MNDXT
MNDXT, Bad Bramstedt
5/2023 – offen (2 Jahre, 3 Monate)
IT & Entwicklung
Tätigkeitszeitraum

5/2023 – offen

Tätigkeitsbeschreibung

I design and develop both Android and backend application for AI content generation app “Mind Extension” -Hyperlink entfernt- using latest Android technologies (Kotlin, Coroutines, Compose, Dagger Hilt DI, MVI, Mockk) and Google Cloud Platform + GitLab CI infrastructure for my backend (Cloud Run, Docker, Ktor, Koin DI, Detekt, Mockk)

As part of this project, I integrated services such as Google InApp Billing, Cloudinary CDN, OpenAI GPT, StabilityAi Stable Diffusion and Firebase SSO and Storage.

Eingesetzte Qualifikationen

Android, Backend, Google Cloud, Kotlin, Mobile Application Development

Senior Android Developer
RTL Group, Remote
2/2022 – 7/2023 (1 Jahr, 6 Monate)
Medienbranche
Tätigkeitszeitraum

2/2022 – 7/2023

Tätigkeitsbeschreibung

With a team of over 250 people (>40 Android devs on one codebase) I'm working on their next generation media streaming solution for RTL. My team is responsible for creating the podcast section of the app. Highlights: Working with a very large team utilising the SAFe framework in a highly modularised project.

Tools and Skills: Kotlin, Dagger/Hilt Dependency Injection, Coroutines, MVVM, Retrofit/okhttp, GitLab, AndroidX, Mockito, Scrum & SAFe, Confluence, Jira, MS Teams, Jetpack Compose

Eingesetzte Qualifikationen

Android, Git, Graphql, Jira, Kotlin, Scrum

Senior Android Developer
Immowelt Hamburg GmbH, Remote, Hamburg
2/2021 – 1/2022 (1 Jahr)
IT & Entwicklung
Tätigkeitszeitraum

2/2021 – 1/2022

Tätigkeitsbeschreibung

Together with the existing Android team I have further developed the Immowelt Search App. Highlight: Designing a polygon draw and erase feature prototype for creating search areas on Google Maps based on the JTS Topology Suite and the Android motion event system.

Eingesetzte Qualifikationen

Android, Design Thinking, Gradle, Jenkins, Jira, Kotlin, Scrum

Senior Android Developer
AOK Systems, Berlin
9/2019 – 12/2020 (1 Jahr, 4 Monate)
Versicherungen
Tätigkeitszeitraum

9/2019 – 12/2020

Tätigkeitsbeschreibung

Begleitungs des Redesigns der AOK Bonus App. Konzeption und Einführung eines Multi-Modul fähigen Single-Activity Navigationssystems unter Verwendung von MVI, RXJava und Magnet DI.

Eingesetzte Qualifikationen

Reactive Programming, Kotlin

(Senior) Android Developer (Festanstellung)
komoot, Potsdam, Berlin, Remote
11/2015 – 9/2019 (3 Jahre, 11 Monate)
Sport und Freizeit
Tätigkeitszeitraum

11/2015 – 9/2019

Tätigkeitsbeschreibung

Development of new features and maintenance for the leading outdoor planning navigation app in DACH - 3M downloads, up to 1M active users (depending on the season of the year).

Eingesetzte Qualifikationen

Android Entwicklung, Java (allg.), Kotlin

Android Developer (Festanstellung)
UnlockYourBrain GmbH, Berlin
4/2015 – 9/2015 (6 Monate)
Medienbranche
Tätigkeitszeitraum

4/2015 – 9/2015

Tätigkeitsbeschreibung

Development of Semper. Semper is a vocabulary trainer app featuring various languages as well as math quizzes using an unique approach by appearing in front of the lockscreen or before apps are started. On its peak the app had several 100k users per month.

Eingesetzte Qualifikationen

SQL, Android, Java (allg.), XML, Json, Representational State Transfer (REST)

Android Developer (Freelancer)
TEC HELP [...] [...], Berlin, Remote
1/2012 – 1/2017 (5 Jahre, 1 Monat)
High-Tech- und Elektroindustrie
Tätigkeitszeitraum

1/2012 – 1/2017

Tätigkeitsbeschreibung

Freelancing as an Android developer working with Random House GmbH as well as in-house apps for Siemens and other start-ups.

Eingesetzte Qualifikationen

Android Entwicklung, Java (allg.), Mobile Application Development, CSS (Cascading Style Sheet), HTML

Ausbildung

International Media and Computing
Master of Science
2015
Berlin

Über mich

I’m a senior Android developer with 10+ years of experience creating high-quality native apps. Since recently I can combine that with cutting-edge generative AI integrations. From Kotlin and Jetpack Compose to OpenAI and Flux, I help teams build modern mobile apps that are smart, fast, and future-ready.

Technologies I Excel In
- Programming Languages & Tools: Kotlin, Java, and more
- Frameworks & Libraries: Jetpack Compose, Mapbox, Ktor, Coil, OkHttp, Room, Retrofit, Coroutines, RXJava
- Development Environments: Android Studio, IntelliJ IDEA, VS Code
- Build & Cloud Tools: Gradle, Jenkins, Firebase, Google Cloud Run, OpenAI, Flux, gen. AI APIs
- Architectures & Patterns: MVVM, MVI, Clean Code, Clean Architecture

Whether you want to modernize your app, add AI-powered features, or build a full product end to end – from concept + design to deployment – I combine deep technical skills with a passion for clean, future-ready solutions.

Let’s build something remarkable together!

Weitere Kenntnisse

Android SDK, Kotlin, Java, AndroidX, ViewBinding, Magnet DI, Koin DI, Mapbox,
Picasso, JodaTime, OkHttp, EventBus, Room, Realm, greenDao,
Retrofit, Timber, Coroutines, RXJava, JUnit, Espresso, Mockito, Robolectric
Play Services, Support Libs/JetPack, Architecture Components,
Jackson/Gson, Toasty, SQLite, Realm DB, greenDAO, Room,
JavaScript/HTML/CSS, Bash, Solidity, React, MVVM, MVI, MVC, DataBinding, Scrum, Confluence, Jira, Bitbucket, Jetpack Compose, Ktor, Google Cloud, Gitlab, gen. AI, GPT, Claude, Kling AI, KI-Chat

Persönliche Daten

Sprache
  • Deutsch (Muttersprache)
  • Englisch (Fließend)
Reisebereitschaft
DACH-Region
Arbeitserlaubnis
  • Europäische Union
  • Schweiz
  • Vereinigte Staaten von Amerika
Home-Office
bevorzugt
Profilaufrufe
3616
Alter
38
Berufserfahrung
15 Jahre und 6 Monate (seit 01/2010)
Projektleitung
1 Jahr

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