Stefan Kassler - C# .NET/WPF Software Developer, 16 Years

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Halle (Saale), Germany

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Experience

Nov 2023 - Jul 2024

9 months

C# .NET/WPF Developer

Hessische Zentrale für Datenverarbeitung

Redevelopment of outdated software used in Hessian schools in C# .NET/WPF
Understanding and analysis of old Delphi and Visual Basic 6 source code
Use of Visual Studio 2022 as IDE
Team collaboration through pull requests and version control with Git/SourceTree
Project management with proprietary wiki software and Open Project
TechStack: C#, .NET 8.0, WPF, Visual Studio 22, Delphi, Visual Basic 6, LDAP, Active Directory, FTP, SMB, Git, SourceTree
Workflow: pull requests, Open Project, weeklies, weekly meetings, dynamic communication

May 2023 - Jun 2023

2 months

C#/.NET Developer

Brooks Automation (Germany) GmbH

Further development of the user interface software for complex semiconductor cleaning machines according to the SEMI standard
Background communication with SPS software for machine control
Use of the Spring.NET Framework alongside standard .NET components
Development in Visual Studio 2019 with ReSharper
Team collaboration via pull requests and version control with Git/SourceTree
Project management with Atlassian Confluence and Azure DevOps
Introduction of a SCRUM model with daily stand-ups
Communication entirely in English
TechStack: C#, .NET Framework, Spring.NET, Git, SEMI Standard, Visual Studio 2019, ReSharper, SPS, Semiconductor

Jan 2022 - Sep 2022

9 months

Full-Stack Developer

TQ-Systems GmbH

Further development of apps on embedded devices, with Go in the backend and Vue.JS in the frontend
Development in an Ubuntu 20.04 LTS VM with Visual Studio Code
Containerization of each app in Docker containers
Quality assurance through unit tests in Go and integration tests with Cypress
Team collaboration with merge requests and version control via GitLab
Automated pipelines in GitLab CI for tests on merge requests
Project management with Jira and Confluence in the SCRUM framework (dailies, weeklies, sprint meetings, retrospectives)
TechStack: Go, Vue.JS, JavaScript, GitLab, Docker, Ubuntu, Visual Studio Code, Webpack, Cypress, MQTT, Modbus, D-Bus, Yocto, Yarn, BASH, Microservices, REST API

Jan 2020 - May 2021

1 year 5 months

Freelance C#/.NET Developer

E.ON Digital Technology GmbH

Continued operation and maintenance of an old CRM program in C#/.NET
Providing conversation guides in form format via vue.js and RTI Designer
Development in Visual Studio 2019, RTI Designer and Visual Studio Code for vue.js/JavaScript
Version control with TortoiseGit
Project management with Jira and Confluence using the SCRUM model (dailies, weeklies)
TechStack: C#, .NET, JavaScript, Vue.JS, node.js, CSS, HTML, RTI Designer, REST API, Webservices, Microservices, SoapUI, Postman, Git Bash, TortoiseGit, CosmosDB, AWS

Jan 2019 - Mar 2019

3 months

Freelance Software Developer

DAVASO GmbH

Analysis and comprehensive documentation of a codebase that had grown over 13 years within 2 months
Adaptation of the software to new legal requirements
Work with Transact-SQL on MS SQL Server, C++ and C#/.NET components, as well as Perl programs
Adaptation and further development of the customer homepage with PHP 7/Zend 1/Composer/Smarty and prototypeJS
Development tools: various Visual Studio versions, MS SQL Server Management Studio, Eclipse Oxygen 3
Version control with WinCVS
Project management with Jira and wiki in the SCRUM framework (dailies, sprints)
TechStack: C#, .NET, C++, MS-SQL Server 2008, PHP 7, Zend 1, JavaScript, jQuery, prototypeJS, Transact-SQL, Composer, Smarty, Perl

Jul 2018 - Dec 2018

6 months

Unity3D/VR Developer

Carmeq GmbH

Further development of a comprehensive driving simulation with VR integration
Simulation of driving and charging scenarios for electric cars with hardware feedback (steering wheel, pedals)
Use of HTC Vive Pro and Leap Motion for hand tracking
Development in Unity3D with VRTK and Visual Studio
Project management with Jira and Confluence
TechStack: Unity3D, C#, mono, VR, AR, HTC Vive Pro, Leap Motion, SVN

Aug 2017 - Sep 2018

1 year 2 months

Delphi Developer

form & function GmbH

Development of a database application in Delphi for planning maintenance processes based on sensor input from industrial plants
Calculation of wear and maintenance intervals
Connection to a PostgreSQL database and existing software portfolio
TechStack: Delphi 10.2, PostgreSQL, zeoslib, dcpcrypt2

Nov 2016 - Aug 2017

10 months

VR Learning Software Developer

LeFx GmbH

Development of VR learning software with gamification elements for the automotive industry
Development of a scenario editor and a custom scripting language with parser and interpreter
Use of Unity3D with VRTK and HTC Vive hardware
Project management with Jira and Confluence
TechStack: Unity3D, C#, mono, VRTK, HTC Vive, UniRx, Perforce

Apr 2015 - May 2016

1 year 2 months

Lead Gameplay Developer

FAKT Software GmbH

Development of level and object editors for "Crazy Machines 3" on the company's own engine
Implementation of complex mathematical functions
Development in C++ with Visual Studio and in-house engine
Version control with Git (SourceTree GUI)
Project management with Jira and Confluence using the SCRUM model (Dailies, One-Week Sprints)
TechStack: C++, 3D programming, physics programming, Visual Studio 13/15

Oct 2013 - Sep 2014

1 year

Startup Software Developer

EXIST-Stipendium

Solely worked on medical software for the early detection of vascular diseases through OCT image analysis
TechStack: Delphi 7, image processing, medical software

Mar 2008 - Sep 2013

5 years 7 months

Founder and Developer

SAFKAS Games

Founded and managed my own software company while studying
Developed games in Delphi 7 and Andorra2D
Implemented small web projects and my own homepage in PHP and JavaScript
TechStack: Delphi 7, Andorra2D, PHP, JavaScript, MySQL, HTML, CSS

Industry experience

See where this freelancer has spent most of their professional time.

Experienced in Information Technology, Manufacturing, Energy, Automotive, Healthcare, and Education.

Information Technology

Manufacturing

Energy

Automotive

Healthcare

Education

Business area experience

See which departments and functions this freelancer has contributed to most.

Experienced in Information Technology, Product Development, Project Management, Research and Development, and Quality Assurance.

Information Technology

Product Development

Project Management

Research and Development

Quality Assurance

Skills

Programming: C#, .Net, Wpf, C, C++, Vue.Js, Javascript, Delphi, Php, Unity3d, Go, Mysql, Ms Sql, Postgresql, Css, Html, Perl, Bash, Typescript, Basic, Turbo Pascal
General Work Approach: Agile Software Development, Scrum, Object-Oriented Programming, Leading Own Development Teams, Source Code And Project Documentation, An Eye For Software Architecture, Creating Specifications, Strong Communication Skills, Team Player, Performance-Oriented
Ides: Visual Studio, Visual Studio Code, Rti Designer, Delphi (2, 5, 7, Xe2, 10, 11), Unity3d, Eclipse
Toolchain: Git, Gitlab, Svn, Sourcetree, Perforce, (Win)Cvs, Docker, Ansible, Cypress, Soapui, Postman, Yocto
Frameworks / Components - Web Development: Vue.Js, Node.Js, Webpack, Angular, Jquery, Symfony, Zend, Prototypejs, Composer, Enyo
Frameworks / Components - C#: .Net, Wpf, Spring.Net, Unity3d, Vrtk, Unirx
Frameworks / Components - Go Lang / Embedded System: Modbus, D-Bus, Sps
Frameworks / Components - Delphi: Zeoslib, Unidac, Mydac, Dcpcrypt2, Andorra2d
Frameworks / Components - General: Mqtt, Microservices, Rest Api, Webservices
Collaboration: Jira, Confluence, Azure Devops, Mantis Bt, Trello, Ms Teams, Skype, Rocket.Chat, Zoom, Discord, Bbb
Hardware: Htc Vive Pro, Leap Motion, Microsoft Hololens
Formats: Json, Xml, Html, Css, Rauc, Pdf, Word, Excel
Operating Systems: Windows (From 95), Ubuntu (From 18.04), Ms-Dos (From 3.0)

Languages

German

Advanced

English

Advanced

Education

Oct 2001 - Jun 2010

Universität Leipzig

Magister · Computer Science, Logic and Philosophy of Science · Leipzig, Germany

Statistics

Experience

Total positions 11

Experience in Information Technology 7.5 y

Avg length 1 y 2 m

Longest experience 5 y 6 m

Expertise

Recent roles C# .NET/WPF Developer, C#/.NET Developer, Full-Stack Developer

Main industries Information Technology, Manufacturing, Energy

Main business areas Information Technology, Product Development, Project Management

Qualifications

Highest degree Master

Member since

June 2025

Last update

October 2026

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Frequently asked questions

Have questions? Find more information here.

Stefan is based in Halle (Saale), Germany and can operate in on-site, hybrid, and remote work models.

Stefan speaks the following languages: German (Advanced), English (Advanced).

Stefan has at least 13 years of experience. During this time, Stefan has worked in at least 11 different roles and for 11 different companies. The average length of individual experience is 1 year and 2 months. Note that Stefan may not have shared all experience and actually has more experience.

Based on recent experience, Stefan would be well-suited for roles such as: C# .NET/WPF Developer, C#/.NET Developer, Full-Stack Developer.

Stefan's most recent position is C# .NET/WPF Developer at Hessische Zentrale für Datenverarbeitung.

In recent years, Stefan has worked for Hessische Zentrale für Datenverarbeitung, Brooks Automation (Germany) GmbH, and TQ-Systems GmbH.

Stefan is most experienced in industries like Information Technology, Manufacturing, and Energy. Stefan also has some experience in Automotive, Healthcare, and Education.

Stefan is most experienced in business areas like Information Technology, Product Development, and Project Management. Stefan also has some experience in Research and Development and Quality Assurance.

Stefan has recently worked in industries like Manufacturing, Education, and Government and Administration.

Stefan has recently worked in business areas like Information Technology, Project Management, and Product Development.

Stefan holds a Master in Computer Science, Logic and Philosophy of Science from Universität Leipzig.

Stefan is immediately available full-time for suitable projects.

Daily rate distribution

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<€640 €640-720 €720-800 €800-880 €880-960 €960-1040 €1040+

The rates shown represent the typical market range for freelancers in this position based on recent contracts on our platform.

Average rates for similar positions

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Daily rate avg. 815 €

The average daily rate is the mean of all daily rates from recent contracts of comparable freelancers on our platform.

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Median rate 800 €

The median daily rate is the middle value of all daily rates — half of comparable freelancers charge less, half charge more. Unlike the average, it is barely affected by outliers.

Calculated based on our freelancers’ daily rates as of 29 Oct 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.