Hi, I'm Michael
Fullstack Developer
Over a decade of experience in software development & consulting - creating clean, maintainable fullstack solutions with Spring Boot & Angular
About Me
Michael Wellner
- Fullstack Developer -
As a Fullstack Developer from Stuttgart, Germany - now in my late 30s - I specialize in building robust, modern backend systems with Spring Boot using Java or Kotlin. My work spans microservice architectures, clean domain models, event‑driven integrations and high‑quality REST APIs. On the frontend side I deliver intuitive Angular applications with a strong focus on usability and maintainability.
With more than a decade of hands‑on experience, I have worked across several industries (Automotive, E‑Commerce, Finance, Healthcare) and built scalable systems based on Postgres/MySQL, Docker, Kubernetes (Dev), CI/CD pipelines and cloud‑ready architecture patterns. I enjoy solving complex technical problems - but always with the goal of creating sustainable, long‑term value.
Recently, I expanded my backend skillset with Kotlin, Spring Boot 4, and Kafka, while refreshing my knowledge in Angular 19+ and Kubernetes. I strongly believe in continuous learning, pragmatic engineering practices, and a developer culture built on collaboration, code reviews and shared standards.
I thrive in environments where people support each other, knowledge flows naturally, and modern tooling enables focused work. To maintain high concentration and minimize context switching, I often use the Pomodoro technique.
In the complex world of code, simplicity is the ultimate sophistication.
Fullstack Dev
Building backend systems with Spring Boot using Java & Kotlin, Spring Cloud and modern microservice patterns, paired with intuitive Angular frontends for responsive and user-friendly applications.
DB & Messaging
Designing clean data models with Postgres and MySQL and implementing event- and message-driven integrations using RabbitMQ or Kafka for scalable, asynchronous system communication.
DevOps
Delivering and operating applications efficiently through CI/CD pipelines (GitLab CI, Jenkins), container orchestration with Docker and Kubernetes, and automation via Bash or lightweight scripting.
Tools
Boosting productivity through expert use of IntelliJ IDEA, Git, GitLab/Jenkins pipelines, Postman, and modern debugging and profiling tools - always with a focus on clean workflows and maintainability.
Concepts
Ensuring long-term quality through Clean Code, automated testing (JUnit, ArchUnit), agile collaboration (Scrum), and domain-driven thinking to model complex business logic effectively.
Professional Journey
Fullstack Software Developer
coming soon... | Remote
Developing microservices with Spring Boot using Kotlin and frontends with Angular...
Transition phase & personal sabbatical
Combined a planned sabbatical with focused technical upskilling: Kotlin with Spring Boot, Kafka fundamentals, Angular 19+, Kubernetes, and general backend refresh. Additionally explored data science and data engineering concepts. Prepared for the next long-term professional challenge.
Team Lead Software Development
sidion GmbH | Remote / Stuttgart
Team lead of an interdisciplinary development team at sidion, fostering an open and supportive team culture through regular meetings and informal virtual exchanges. Served as the main contact for both professional and personal matters, supported career development, and handled goal setting.
Senior Software Developer
sidion GmbH | Remote / Stuttgart
Contributed to complex client projects in the finance and healthcare sectors, focusing on the development of modern Java-based microservice applications. Supported architectural decisions, promoted clean code practices, mentored junior developers, and worked in agile Scrum teams using a broad technology stack.
Professional Software Developer
sidion GmbH | Stuttgart
Worked on various client projects across automotive, logistics, banking, and e-commerce sectors, focusing on developing modern Java-based microservice applications. Used a wide range of technologies, worked in agile Scrum teams, mentored junior developers, and emphasized clean code practices.
Junior Software Developer
sidion GmbH | Stuttgart
Contributed to a client project in the automotive industry, focusing on software development using Java, SQL, XML, and IBM DB2. Supported requirements engineering and worked with project management tools like JIRA and Confluence.
Junior Consultant Automotive Engineering
wontec GmbH | Weissach
Worked in product data management at Porsche AG, focusing on optimizing product data integration within the Volkswagen Group. Responsible for an interface between SAP and an IBM host, and developed VBA tools in Excel for project management and quality assurance.
Skills & Experience
Development
Frameworks & Libs
Tools
Concepts
DB & Messaging
Infrastructure
OS
I primarily develop on macOS for its great developer experience, but prefer Linux (Ubuntu/Debian) for server and container workloads.
Stuff
Other stuff with which I have also been able to gain experience here and there
Recent Projects
MaverickWave
A lightweight, modern CSS framework for building responsive websites with elegance and speed.
Build stunning, responsive websites effortlessly with a modern, lightweight CSS framework crafted for speed, style, and flexibility.
Idently
A tiny, stateless, code-based Deno identity server with code login and a JSON client-user store.
Sometimes you don't need OAuth, Firebase, or Keycloak. You just want a damn code and a JWT.
versions
A bash script to display the version numbers of your tools.
I just want to see the version numbers of all my used tools with one command.
Blog Posts
Spring Boot 4 - What’s New and Why It Matters for Developers
Spring Boot 4 (GA expected in November 2025) is built on top of the new Spring Framework 7 - and it’s more than a version bump. This release is a structural upgrade that modernizes how Spring applications are built, configured, and deployed. For developers running Java applications in production today, this version delivers meaningful improvements in startup performance, modularity, and developer experience.
Kotlin and Spring Boot for experienced Java developers - A practical introduction
After eight years of shipping services in Java & Spring Boot, I took over a week to really try Kotlin. I expected “Java but nicer.” What I found is a language that feels familiar in all the right places and surprisingly opinionated where it matters.
Data-Oriented Programming in Java - More Data, Less Magic
Data-Oriented Programming in Java promotes modeling data as immutable structures and separating behavior into services. With Java's record, sealed interface, and pattern matching, this approach becomes clean and powerful - enhancing readability, testability, and domain clarity compared to traditional object-oriented design.
Tired of Auth Overkill? Meet idently - Simple, Stateless Deno Identity Gets Smarter
At its heart, idently is my take on dead-simple, stateless authentication built with Deno. The core idea? Forget emails and passwords. Just give users a secret code. They send the code, they get a JSON Web Token (JWT) back.
MaverickWave - I finally published my own CSS framework
After countless false starts over the years, I'm excited to finally share MaverickWave with you - a lightweight, responsive CSS framework I've built for modern web development. This project represents not just code, but a personal milestone in my journey as a developer.
My Digital Handshake - Why I Built My Portfolio Page
My portfolio page at m1well.com isn't just a list of skills or a digital resume - it's my professional statement, a carefully crafted space designed to tell you who I am as a developer.