Glad you found the way to my homepage. I am a freelance software engineer with many years of practical experience in the industry doing mainly system design and programming.

Over the last couple of years I was involved in many projects in the fields of Android, Automotive and Connected Car. But other topics are just as welcome, with roles as software architect, team lead and definitely also hands-on development.

If you are interested in my services, please send me an email or simply call me.

Top Skills



Mobile Architecture

C / C++


Team Lead

Automotive / Connected Car



Mac OS



Android & Backend Architect (Automotive)

05/2016 - 06/2023
Automotive Company, Germany

Android & Backend Architect and Lead Developer (Automotive) for a company which develops vehicle-engine-tuning modules. A newly developed smartphone application communicates with the tuning-module via Bluetooth Classic & Low Energy to adjust car-tuning parameters and select programs. There are several hardware variants of the modules, which are each controlled by a separate app. All these apps can be generated from the same source code base, so that code maintenance is less complex. Each application also connects to a central backend via REST API to send module data and statistics and download updated configurations or firmware. I was responsible for design and development of the Android app and the backend, additionally I was coordinating the iOS development.

Android Architect

07/2022 - 06/2023
Mobility Solutions Provider, Berlin

Maintenance of an existing fleet management app and design of a framework for a new app to be installed on Android custom hardware in the fleet’s vehicles.

Android Architect

03/2022 - 04/2022
quo connect GmbH, Berlin

Android UI and Service framework for an app to be deployed in a locomotive cab to help the driver choose an efficient driving strategy. The business logic was completely implemented by the customer and runs in a background service. I was responsible for setting up a state-of-the-art Android framework so that the background service can communicate with the UI components asynchronously and according to the MVVM concept. I also realized some dynamic graphical UI components.

Android & Backend Architect

10/2018 - 10/2021
Bundesdruckerei, Berlin

Design and implementation of several Android apps to enable users to administer their private data and provide access permissions to third parties for viewing the user’s private data in accordance with the European GDPR. Additionally design and implementation of a backend with REST-API to access the privacy/permissions database for logged in users. This REST-API can be used by the above mentioned Android app and also by other clients (e.g. iOS, web app).

Android Architect

03/2020 - 03/2021
NAS GmbH, Berlin

Framework and part of an app for local public transport in Nuremberg. Design and implementation of a chat module with WhatsApp-like functionality, including text chat with embedded multimedia elements (pictures and other documents). Users can chat with customer support and subscribe to news and traffic updates, with WhatsApp like functionality and UI. Communication with the backend via REST API.

Android Architect

Package Delivery Company, Germany

App-prototype for an app for package delivery agents. Proof-of-concept and Android application framework for an app which will run as the only application in kiosk mode on a rugged device. The user will be able to start a Google Maps turn-by-turn navigation from the app. When the navigation is completed or cancelled, the kiosk-mode app will take back control.

Android Architect

Payment Solution Provider, Germany

Android App Prototype for a payment solution. A client app (e.g. shopping app) sends the payment data to a payment provider server app on the same device. The payment server app then displays an overlay UI with the payment details on top of the client app. Now the user can confirm the payment. In a real world use case the payment server app would then handle the payment transaction with the payment provider backend, but that was not part of the prototype.

Android Architect (Automotive)

04/2017 - 03/2018
SCANIA Germany, Koblenz

Android Architect (Automotive) for SCANIA Deutschland. Concept and implementation of an Android native tablet app for damage assessment of truck rental returns. The app embeds an existing web app and extends it with native functionality (camera, image editor). Communication with an existing backend via REST API.

Android Architect/Developer

09/2017 - 12/2017
T-Systems Multimedia Solutions, Dresden

Android Architect/Developer for T-Systems Multimedia Solutions. Concept and basic building blocks of a framework for development of a native Android email app.

Android Architect/Developer

contura Modellbau, Berlin

Android Architect/Developer for contura Modellbau, Berlin. Concept for and development of an Android native tablet app with connection to external hardware via Bluetooth LE. The app runs in kiosk-mode on a tablet which is embedded in an architectural model. Users can press external hardware buttons to invoke functions within the tablet app, e.g. to play videos.

Android Architect/Developer

02/2017 - 04/2017
Social-Media Company, Germany

Android Architect/Developer for a German social media company. Development of a location based messaging functionality for a students’ app. With this students can post text and images to a public group board and rate the postings of other participants. Communication with an existing backend via REST API.

Android Architect (Automotive)

09/2015 - 10/2016
Mobility Media GmbH (BOSCH), Berlin

Android Architect for Mobility Media GmbH, a BOSCH subsidiary in Berlin. Responsible for the communication with offshore and nearshore development teams, creating concepts for technical architecture, security assessments, all for a Connected-Car project and accompanying SDK for Android, iOS which connects to a backend/portal system.

Android Architect (Automotive)

04/2015 - 08/2015
VOLKSWAGEN AG, Abt. AppFactory, Wolfsburg

Android Architect (Automotive): Redesign of an Android-App which is part of vehicle fleet administration system with automated driver’s logbook, logging of routes, petrol stops, driver’s authentication, with direct connection to vehicle via OBD2/bluetooth to query the available vehicle parameters. The app will now be connected to a new backend server and the evaluation of car values will be enhanced.

Android Architect (Automotive)

04/2015 - 05/2015
VOLKSWAGEN AG, Abt. AppFactory, Wolfsburg

Android Architect (Automotive): Enhancement of the Android-Wear smartwatch application which was started at the end of 2014 and served as a Connected-Car showcase for car expos. The Android companion app can now also be displayed on tablets and includes new scenarios for the showcase, including Digital Car Key functions.

Android Architect (Automotive)

04/2015 - 05/2015
VOLKSWAGEN AG, Abt. AppFactory, Wolfsburg

Design and implementation of an Android device driver and an Android test application for a Bluetooth-OBD-Dongle in a car. The connection is first established on the Bluetooth layer and then cryptographically authenticated. The test application enables the subscription and display of current car values, such as fuel consumption etc.

Android Architect (Automotive)

03/2015 - 04/2015
VOLKSWAGEN AG, Abt. AppFactory, Wolfsburg

Android Architect (Automotive): Concept for modularization and documentation for an app framework to be used for the Android apps of Volkswagen AG.

Android Architect

02/2015 - 03/2015
App Agency, Berlin

Architecture and implementation of Google Deep Linking in one of the most popular German-language weather apps with several million downloads. The new functionality had to be embedded into the existing application framework and unit tests had to be implemented.

Android Architect (Automotive)

12/2014 - 03/2015
VOLKSWAGEN AG, Abt. AppFactory, Wolfsburg

Review and technical redesign of an Android app in the field ConnectedCar. The app connects to a car via a Bluetooth-OBDII dongle. The user can view current and historical data on his smartphone, such as fuel consumption, driver log, error and maintenance messages etc. The customer is Volkswagen AG who will offer the app and dongle as an accessory for his cars.

Android Architect (Automotive)

12/2014 - 01/2015
VOLKSWAGEN AG, Abt. AppFactory, Wolfsburg

Android showcase-app for display of wrong-way drivers on highways which are detected automatically. The time and coordinates will be displayed in the app, accompanied by a Google map display. This is part of a research project by a major German car manufacturer who wants to integrate such a display in his cars. Additionally various other aspects of the research project are being visualized in the app.

Android Architect (Automotive)

10/2014 - 02/2015
VOLKSWAGEN AG, Abt. AppFactory, Wolfsburg

Android Wear smart-watch application, a Connected-Car showcase to be shown on an auto fair. The user can select certain functions on his Android Wear smart-watch which will be triggered on the connected car, e.g. unlock/lock doors, media player functions etc. Additionally certain information from the car can be displayed on the user’s watch, like fuel consumption, fuel capacity, mileage etc. The customer is Volkswagen AG who considers implementing such functionality in production cars.

Android Architect (Automotive)

09/2014 - 10/2014
VOLKSWAGEN AG, Abt. AppFactory, Wolfsburg

Android tablet app, a showcase for a security solution for big trucks. The showcase runs on several Nexus 10 tablets which communicate in a LAN. One of the tablets will act the role of a burglar who can enter the truck’s security zone. If that happens an alarm will be triggered on the other tablets which can act as either truck driver or fleet administration. The alarm will be displayed graphically and acoustically on the other tablets as well as a photo of the burglar will be taken and transmitted over the network. The customer is Volkswagen AG who intends to develop a procuction security solution based on this showcase.

Android Architect (Automotive)

07/2014 - 09/2014
VOLKSWAGEN AG, Abt. AppFactory, Wolfsburg

Android-App which is part of vehicle fleet administration system with automated driver’s logbook, logging of routes, petrol stops, driver’s authentication, with direct connection to vehicle via OBD II / Bluetooth to query the available vehicle parameters. The logged data is being synchronized via JSON/REST-API with the vehicle fleet administration system which runs on a SAP backend. The customer is Volkswagen AG who markets the solution as part of vehicle fleet sales.

Android Lead Developer

01/2014 - 06/2014
Corussoft GmbH, Berlin

New versions of some trade fair info apps under Android:, e.g. for “ILA Air Show” in Berlin, SMM ship fair in Hamburg, furthermore “ITB Berlin”, “nortec”, “Reisen Hamburg”, “Best of Events”, “HansePferd”. The app reads the trade fair data from a web service and stores the data in an internal SQLite database. The information is presented to the user in a well structured way. The user can save favorites, take notes, save contacts and phone or email the exhibitors from within the app. These apps are based on the framework developed by me in 2011/2012.

Lead Developer

09/2013 - 11/2013
Berlinux GmbH, Berlin

C++ projekt: server monitoring in mainframe + Unix data centers, log file monitoring, data format conversion, data verification, data repair.

Android Lead Developer

03/2013 - 09/2013
PocketWeb GmbH, Berlin

Android app for medical/fitness, with pedometer and activity statistics, graphic evaluation, login and storage on a server.

Android Lead Developer

01/2013 - 06/2013
ISV GmbH, Berlin

Android app for local ads, with photo and Google Map view, communication with a server.

Android Lead Developer

06/2012 - 09/2012
Corussoft GmbH, Berlin

Android app for regional tourism including Google Maps functions and location aware techniques, picture gallery and a very fast and versatile search function in the directory listing. Search results can be displayed in a list or as interactive pins on a map. This app will also serve as a framework for upcoming regional tourism apps.

Android Lead Developer

11/2011 - 05/2012
Corussoft GmbH, Berlin

Trade fair info apps under Android:, e.g. for “ILA Air Show” in Berlin, SMM ship fair in Hamburg, furthermore “ITB Berlin”, “nortec”, “Reisen Hamburg”, “Best of Events”, “HansePferd”. This app was designed and developed from scratch using an existing iOS app as a model. The app reads the trade fair data from a web service and stores the data in an internal SQLite database. The information is presented to the user in a well structured way. The user can save favorites, take notes, save contacts and phone or email the exhibitors from within the app. Furthermore this app serves as a framework for a whole series of similar trade fair apps.

Android Lead Developer

09/2011 - 10/2011
Touching Code GmbH, Berlin

E-Book App for Android, using the existing iOS app “Fingerspiele” as a model.

CEO App Development Company

2010 - 2011
Touching Code Ltd., Bangkok

CEO of Touching Code Ltd. in Bangkok, Thailand. Focus: Android App development.

Android Lead Developer

04/2010 - 06/2010
Touching Code GmbH, Berlin

Small showcase app for Android / iOS for a software company that develops apps for both platforms. This app displays poems which are downloaded from a webservice.

Lead Developer

2009 - 2010
ISV GmbH, Berlin

Part of development team of a classified ad app (iOS + Android) which is used by many publishing companies all over the world

Lead Developer

ISV GmbH, Berlin

Design/implementation of a native Apple iPhone multimedia application which acts as a client of an enterprise application server.

Lead Developer

2006 - 2007
ISV GmbH, Berlin

Design/implementation of SOA components in PowerBuilder-Sybase-EAServer project for integrated print+web solutions.

Lead Developer

ISV GmbH, Berlin

Design/implementation of a solution to store credit card data securely in a RDBMS using Triple-DES.

Lead Developer

2002 - 2005
ISV GmbH, Berlin

Various enhancements (hyphenation, spellchecker, Unicode) to the before mentioned WYSIWYG-Editor and to the newspaper ad-taking application.

Lead Developer

2000 - 2001
dots GmbH, Berlin

Java-Client with GUI (using Swing) and C++-Server, part of a professional print management software package.

Lead Developer

PACE GmbH, Berlin

C++ Windows application for recognizing text in TV broadcasts (using Abbyy FineEngine OCR and Hauppauge WinTV SDK).

Lead Developer

1999 - 2000
CSnet GmbH, Berlin

BMC Patrol Knowledge Modules, e.g. a versatile logfile adapter and Netware print server monitoring.

Lead Developer

1996 - 1998
ISV GmbH, Berlin

Design/Implementation of the kernel of a major newspaper ad-taking application (using Sybase).

Senior Developer

1994 - 1996
ISV GmbH, Berlin

WYSIWYG-Editor implemented as Windows DLL for a PowerBuilder application.

Senior Developer

1992 - 1993
ISV GmbH, Berlin

Voice mail kernel and -applications with interface to Oracle database.

Lead Developer

Westfalia Systemtechnik, Borgholzhausen

Inter process communication module on top of Novell IPX/SPX

Lead Developer

1990 - 1991
Klöcker & Funke GbR, Berlin

Design/Implementation of an OO programming language (compiler, runtime, RDBMS interface…) for WILD AG, Heidelberg

Lead Developer

Westfalia Systemtechnik, Borgholzhausen

Design of an event-oriented UI for dumb terminals (runtime system + UI description language + translator)

Lead Developer

1988 - 1990
Westfalia Systemtechnik, Borgholzhausen

Large warehouse realtime control and management system including implementation of a DBMS

Senior Developer

ANCOS GmbH, Berlin

Operating system for a fault tolerant multi-processor-system (underwater robot).

Junior Developer

1985 - 1986
INLINE GmbH, Berlin

Design/Implementation of the geometry kernel for a 2D CAD application.

Skills & Tools

Industries & Sectors

  • Automotive
  • Publishing Print
  • Publishing Online
  • Logistics
  • Mechanical Engineering
  • Telecoms
  • Radio/TV
  • Public Administration
  • Banks
  • IT-Services
  • Food Industry
  • Aviation
  • Tourism
  • Health system
  • Public Transport

Products / Standards / Technologies

  • Google Android SDK/NDK app development (Smartphones, Tablets, Android Wear Smartwatch)
  • Android Studio / IntelliJ
  • Eclipse (Android, Java, C++)
  • Apple iPhone iOS native app development
  • Windows Systemprogrammierung
  • MS Visual Studio (C++, C#, VBA)
  • Apple Xcode
  • Borland C++
  • Borland JBuilder
  • objektorientierte Entwicklung (OOA/OOD/OOP)
  • Agile Software Development, SCRUM Master
  • BMC Patrol KM Entwicklung
  • Triple-DES Verschlüsselung
  • Revision Control: git, Subversion SVN, Mercurial, CVS, SourceTree, TortoiseSVN, gitGUI
  • Build Tools: Gradle, Maven, Ant, Make
  • Atlassian JIRA, Portfolio, Confluence, Stash, SourceTree
  • Mantis
  • JMeter, RESTClient
  • OpenAPI / Swagger
  • Reactive Programming, RxJava, RxAndroid
  • Clean Code

Android Frameworks / Know-How

  • Android SDK
  • Android Wear
  • Android Architecture Components
  • Android Jetpack Components
  • Android Security / Reverse Engineering : Apktool, jadx, bytecode-viewer
  • DexGuard / ProGuard app hardening
  • Android Google Maps API V1 / V2
  • Android Frameworks for Bluetooth & Bluetooth LE
  • Android Kiosk Mode
  • Google Play Services
  • Google ActionBarCompat
  • Google Android Location API
  • ActionBar Sherlock
  • Google GSON
  • basic-http-client / AndroidHttpClient (Chandler) - XML Pull Parser
  • greenrobot / EventBus
  • SQLite
  • Realm
  • Unit tests: JUnit, Espresso
  • Retrofit
  • Dagger
  • RxJava
  • MVP and MVVM architecture

Data communication

  • Bluetooth / Bluetooth LE
  • Ethernet
  • Internet, Intranet
  • Proprietary protocols
  • RPC
  • RS232
  • SMTP
  • SNMP
  • TCP/IP
  • UUCP
  • Windows Networks
  • Winsock

Programming Languages

Hands-on experience in these languages:

Language                                               since
C 1986
C++ 1990
Java 1999
Kotlin 2017
JavaScript 2005
HTML, XML 1999
Shell (sh, tcsh, bash) 1990
yacc/lex 1992
Imake, GNU-Make
Macro languages
Objective C 1990
Pascal 1986
Powerbuilder 1995
Script languages


Database                                           since
SQL 1985
Oracle 1990
Postgres 2000
Sybase 1991
MS SQL Server 1997
MySQL 2000
SQLite 2010
Adabas 2000
DB2 2000
ODBC 1995
Realm 2016
CortexDB 2018


Type                                                      OS
Apple Mac MacOS X
Apple iPhone / iPad iOS
Android Phones, Tablets Android
Android Wear Watch Android
NeXT Cube / Station NEXTSTEP
PC Windows, Linux
Echtzeitsysteme RTOS
Embedded Systeme various
Proprietäre HW various
Siemens MX ORG/M
Control systems various
SUN Solaris


Language                                              Level
German native
English professional
Spanish advanced
Portuguese basic
Thai basic


1983-1988 Computer Science at TU Berlin, focus on software engineering, embedded software, operating systems, languages and compilers
1990 Certified NeXT Developer (NEXTSTEP)
1991 Object Oriented Programming and Design (ACM training course)
1999 Certified BMC Patrol Knowledge Module Developer
2010 Certified ScrumMaster (Scrum Alliance / Boris Gloger)