Stephan Müller-Ziebur

Developer. Architect. Entrepreneur. Builder.

Senior Java Backend Developer | Software Architect | AI Application Developer


From software developer to entrepreneur and back to what I enjoy most: building software and solving complex technical challenges.

I am a software developer, architect and entrepreneur with more than 25 years of professional experience in software development, enterprise integration and digital product delivery.


Open for New Opportunities

I am interested in discussing opportunities where I can contribute my experience in backend development, software architecture and AI-powered applications — whether as a permanent team member, contractor or freelance consultant.

Backend Development

Java, Quarkus, Spring, Struts, REST APIs, microservices, enterprise integration and backend platforms.

Software Architecture

Pragmatic architecture, scalable systems, integrations and maintainable software solutions.

AI Applications

LLMs, local AI assistants, Whisper, RAG concepts and AI-powered business workflows.


Current Technology Focus

Backend: Java 21+, Quarkus, Spring, Struts, REST APIs, JAX-RS, Microservices, OAuth2, JWT

Cloud & Infrastructure: Docker, AWS S3, AWS SQS, Linux, macOS, containerized deployments

Build, CI/CD & Quality: Gradle, Maven, Git, GitLab CI/CD, Jenkins, JUnit, Checkstyle, SonarQube, Code Reviews

Databases & Data Processing: PostgreSQL, MariaDB, MySQL, Oracle, DB2, MS SQL Server, JSON, XML, CSV processing, data migration and transformation

AI & Emerging Tech: Large Language Models, LM Studio, Whisper, Speech-to-Text, Text-to-Speech, Prompt Engineering, RAG concepts, local AI infrastructure

Enterprise Experience: CMS platforms, media and publishing systems, Jive, SharePoint, Hibernate, Tomcat, WebSphere, JBoss / WildFly, JSP, JSF, Struts


AI Experience

My focus is not on training foundation models, but on integrating AI into real-world applications, workflows and enterprise systems.

  • Built local AI assistants using Large Language Models
  • Integrated Whisper-based Speech-to-Text
  • Implemented Text-to-Speech workflows
  • Worked with LM Studio and locally hosted models
  • Designed conversational workflows and session handling
  • Explored RAG-style knowledge systems
  • Built Python-based AI prototypes and tools

My goal is to combine more than 25 years of software engineering experience with modern AI technologies to build intelligent, reliable and maintainable software solutions.


Recent Projects

Since 07/2024 – Java Backend Developer, eThinking GmbH

Backend development for large CMS-based websites and media platforms using Java, Quarkus, REST APIs, Docker, Gradle and GitLab CI/CD.

07/2023 – 05/2024 – Schaeffler: Intranet Data Migration

Migration of an intranet platform for approximately 80,000 employees from Jive to SharePoint. Development of Python-based migration scripts using REST APIs, OAuth2, JSON export, link rewriting and content transformation.

10/2022 – 07/2023 – Porsche: Intranet Upgrade

Upgrade and customization of a Jive-based intranet platform using Java, Spring, Struts, HTML, CSS, Freemarker and Soy templates.


Professional Background

  • Started programming at age 14
  • Sold first software at age 16
  • Studied Computer Science at the Technical University of Berlin
  • Worked as developer, senior developer, architect, consultant, technical lead, product manager and CEO
  • Founded and managed a software company with up to 30 employees
  • Worked on more than 100 software projects
  • Now focused again on hands-on backend and AI application development

Selected Customers

Adidas · Allianz · Audi · Schaeffler · Porsche · Daimler · Deutsche Bank · Deutsche Telekom · Jive Software · RTL.de · T-Systems · Coca Cola


Why Work With Me?

I bring the perspective of a developer, architect and entrepreneur. I understand clean code, delivery pressure, business priorities and customer expectations. I can work hands-on in the codebase while also helping teams make pragmatic technical decisions.

Open to discussing software engineering, architecture, technical leadership and AI application development opportunities.

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