Karl Forstner - Software / Data-Engineer

Q: Where is Karl based?

Karl is based in Gleißenfeld, Austria and prefers 100% remote projects.

Q: What languages does Karl speak?

Karl speaks the following languages: German (Native), English (Intermediate) .

Q: How many years of experience does Karl have?

Karl has at least 3 years of experience. During this time, Karl has worked in at least 9 different roles and for 7 different companies . The average length of individual experience is 4 months . Note that Karl may not have shared all experience and actually has more experience.

Q: What is Karl's latest experience?

Karl's most recent position is Automated development of processes for XML invoice formats at CIO.pro e.U. .

Q: What companies has Karl worked for in recent years?

In recent years, Karl has worked for CIO.pro e.U. , Forstner Software Solutions e.U. , ONE-PATH Solutions | ONE-CODE , Onecept GmbH , and Techexx GmbH .

Q: Which industries is Karl most experienced in?

Karl is most experienced in industries like Information Technology , Retail , and Sport . Karl also has some experience in Media and Entertainment .

Q: Which business areas is Karl most experienced in?

Karl is most experienced in business areas like Information Technology , Product Development , and Business Intelligence . Karl also has some experience in Project Management , Quality Assurance , and Strategy .

Q: Does Karl have any certificates?

Karl has 5 certificates . Among them, these include: Microsoft Applied Skills: Improving Agents with Autonomous Capabilities , Microsoft Applied Skills: Classes, Properties, And Methods In C# , and Microsoft Applied Skills: Developing an ASP.NET Core web application that uses an API .

Q: What is the availability of Karl?

Karl will be available part-time from June 2026 .

Recommended expert

Gleißenfeld, Austria

Check rate

Experience

Nov 2025 - Present

7 months

Automated development of processes for XML invoice formats

CIO.pro e.U.

Automated parsing and validation of XML invoice formats (e.g., ebInterface, UBL, EBOR)
Structured transfer of data to an ERP system
Implementation using .NET and C#

Sep 2025 - Present

9 months

Founder | Software Engineer / Architect

Forstner Software Solutions e.U.

Development of custom .NET and C# software solutions
Modernization of existing systems from conception and development to cloud deployment in Azure
Focus on high-performance, future-proof B2B software with AI-powered features
Close collaboration with clients to optimize business processes and increase efficiency

Sep 2025 - Present

9 months

Software Engineer

ONE-PATH Solutions | ONE-CODE

Technical implementation of ONE-PATH as part of ONE-CODE.ONE
Development of secure, scalable applications from prototypes to production-ready systems
Platform architecture and programming
Integration of data and knowledge
Development of AI-powered solutions for everyday work

Sep 2025 - Present

9 months

One-Hub development of a scalable data hub

Onecept GmbH

Development of a scalable data hub in the ONECEPT ecosystem for data integration and structuring
Focus on modular architecture, API connectivity, and Blazor-based frontends
Integration of AI features such as semantic search (RAG), role and user management
Flexible deployment options (cloud or on-premises) and GDPR-compliant usage

Jul 2024 - Aug 2025

1 year 2 months

Kiway web application with AI

Techexx GmbH

Architecture, design, and implementation of a comprehensive web application for internal process mapping with AI
Independent implementation of frontend, backend, and data model
Deployment in Azure including migration of the self-hosted environment
Technologies: ASP.NET Core Web API, .NET Blazor WASM, MudBlazor, SignalR, Azure Container Apps, PostgreSQL, Playwright.NET, xUnit

Jul 2024 - Aug 2025

1 year 2 months

Software Engineer

Techexx GmbH

Designing, architecting, and developing business software based on ASP.NET Core Web API, Blazor WebAssembly, and PostgreSQL
Programming in C# and JavaScript
Data modeling and API integration
Project coordination with Jira
Deployment with Docker and Azure Container Apps
Quality assurance through unit and integration tests (Playwright.NET, xUnit)

Jan 2024 - Mar 2024

3 months

MS SQL Server Migration

Mediashop GmbH

Migration from MS SQL Server 2016 to 2022, including SSIS and SSAS upgrade
Adjusting database drivers and developing new logic for changed data type returns

May 2023 - Feb 2024

10 months

FitMatch App Development

Private Client

Developing an app to connect fitness enthusiasts, focusing on shared activities and social interaction
Contributing to concept, UX/UI, frontend and backend development, as well as market analysis and strategy
Integrating premium features, event bookings, and personalized fitness data
Technologies: ASP.NET Core Web API, .NET MAUI Blazor, MudBlazor, Azure App Services, Azure PostgreSQL

Sep 2022 - Mar 2024

1 year 7 months

Software Data Engineer

Mediashop GmbH

Enhancing the data warehouse and automating data processes with SSIS and SSAS
Developing new logic to adapt to changes in data type returns
Creating management reports and dashboards with Power BI
Optimizing SQL queries and automating reporting processes to improve efficiency
Maintaining the internal DWH

Sep 2022 - Jan 2024

1 year 5 months

ETL & Reporting Development

Mediashop GmbH

Developing and automating SSIS pipelines and reporting structures
Creating reports with Power BI and maintaining the internal DWH
Increasing the efficiency and quality of data processes to support data-driven decisions

Industry Experience

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

Experienced in Information Technology, Retail, and Sport.

Information Technology

Retail

Sport

Business Area Experience

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

Experienced in Information Technology, Product Development, Business Intelligence, Project Management, Quality Assurance, and Strategy.

Information Technology

Product Development

Business Intelligence

Project Management

Quality Assurance

Strategy

Summary

Karl Forstner combines modern software development with data engineering and technical system architecture. His focus is on developing scalable platforms, applications, ETL pipelines, and data solutions, as well as integrating structured and unstructured data into productive enterprise systems. As the managing director of ONECEPT GmbH and the main developer of the ONE-HUB product, he guides projects from conception through architecture to production-ready cloud and on-premises deployments.

Skills

.Net / Asp.Net Core
Fullstack Development
Software Architecture
Blazor / C#
End-To-End Implementation Of Modern Web Applications
Modular, Scalable System Designs
Javascript / Rest Apis
Postgresql / Mssql
Etl Pipelines
Api Development
Data Integration And Transformation Processes
Rest Apis And Ssis / Ssas
System Integration
Docker / Azure
Hub Systems
Ai Integration
Signalr / Playwright.Net
Integration Of Data, Knowledge, And Processes
Ai-Powered Features For Businesses
Xunit

Languages

German

Native

English

Intermediate

Certifications & licenses

Microsoft Applied Skills: Improving Agents with Autonomous Capabilities

Microsoft Applied Skills

Microsoft Applied Skills: Classes, Properties, And Methods In C#

Microsoft Applied Skills

Microsoft Applied Skills: Developing an ASP.NET Core web application that uses an API

Microsoft Applied Skills

Microsoft Applied Skills: Developing generative AI apps with Azure OpenAI and Semantic Kernel

Microsoft Applied Skills

Microsoft Applied Skills: Generating Reports with AI Research Assistants

Microsoft Applied Skills

Statistics

Experience

Total positions 10

Experience in Information Technology 2.5 y

Avg length 10 m

Longest experience 1 y 6 m

Expertise

Recent roles Automated development of processes for XML invoice formats, Founder | Software Engineer / Architect, Software Engineer

Main industries Information Technology, Retail, Sport

Main business areas Information Technology, Product Development, Business Intelligence

Qualifications

Certifications earned 5

Profile

Created

May 2026

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Frequently asked questions

Have questions? Find more information here.

Where is Karl based?

Karl is based in Gleißenfeld, Austria and prefers 100% remote projects.

What languages does Karl speak?

Karl speaks the following languages: German (Native), English (Intermediate).

How many years of experience does Karl have?

Karl has at least 3 years of experience. During this time, Karl has worked in at least 9 different roles and for 7 different companies. The average length of individual experience is 4 months. Note that Karl may not have shared all experience and actually has more experience.

What roles would Karl be best suited for?

Based on recent experience, Karl would be well-suited for roles such as: Automated development of processes for XML invoice formats, Founder | Software Engineer / Architect, Software Engineer.

What is Karl's latest experience?

Karl's most recent position is Automated development of processes for XML invoice formats at CIO.pro e.U..

What companies has Karl worked for in recent years?

In recent years, Karl has worked for CIO.pro e.U., Forstner Software Solutions e.U., ONE-PATH Solutions | ONE-CODE, Onecept GmbH, and Techexx GmbH.

Which industries is Karl most experienced in?

Karl is most experienced in industries like Information Technology, Retail, and Sport. Karl also has some experience in Media and Entertainment.

Which business areas is Karl most experienced in?

Karl is most experienced in business areas like Information Technology, Product Development, and Business Intelligence. Karl also has some experience in Project Management, Quality Assurance, and Strategy.

Does Karl have any certificates?

Karl has 5 certificates. Among them, these include: Microsoft Applied Skills: Improving Agents with Autonomous Capabilities, Microsoft Applied Skills: Classes, Properties, And Methods In C#, and Microsoft Applied Skills: Developing an ASP.NET Core web application that uses an API.

What is the availability of Karl?

Karl will be available part-time from June 2026.

What is the rate of Karl?

Karl's rate depends on the specific project requirements. Please use the Meet button on the profile to schedule a meeting and discuss the details.