Tim Rutana · Full-Stack Developer
Clean code for complex systems.
Full-stack engineering with robust Java & Spring backends and React frontends, plus agile coaching and writing about building AI applications.
About
Senior developer, agile coach, and relentless modernizer of legacy systems.
I'm an experienced Senior Software Developer with deep expertise in backend development using Java, and growing skills in frontend development with React. I'm passionate about clean code, modernizing complex legacy systems, and building robust test suites that support fast, confident delivery. I also serve as a Scrum Master and Agile Coach, helping teams adopt Agile practices and ship better software. On top of that, I actively contribute to hiring and onboarding, helping to grow high-performing teams. Always curious and eager to improve, I'm committed to continuous learning and staying on top of evolving technologies and practices.
Skills
Development
Java, Kotlin, TypeScript, JavaScript. Spring, Spring Boot, ReactJS, JUnit, Mockito.
Tools & Infrastructure
Git, Docker, Kubernetes, Jenkins, Gradle, Maven, Tomcat, Splunk.
Methodologies & Practices
Agile Development, Pair Programming, Test Driven Development (TDD), Clean Code, Clean Architecture, Coaching.
AI Tools
Claude Code, Gemini, Antigravity.
Work Experience
Freelance Software Engineer
Working independently on client projects as a freelance software engineer. Built a tax software solution and an IoT payment portal. Beyond development, I also take care of the full ops side with self-hosted infrastructure, deployment pipelines, and server management.
Senior Software Developer at SAP SE
Backend-focused developer working on SAP SuccessFactors, a leading cloud-based HR system. Led efforts to modularize a monolithic architecture, improve test coverage, and advocate Clean Code and Test-Driven Development. Also served as Scrum Master and Agile Coach, supporting Agile transformations and coaching teams. Actively involved in hiring, onboarding, and internal knowledge sharing through lightning talks and technical sessions.
Software Developer at MediaMarkt | Saturn (Media Saturn IT-Services GmbH)
Contributed to a large-scale e-commerce platform and internal CMS using Java, Spring Boot, Angular, and React, all within a microservices architecture on Google Cloud. Worked on key features like the product detail page and a location-based store finder using Google Maps API. Participated in the API Council, promoting an API-first approach across teams.
Android Developer at CHECK24
Developed and maintained Android apps for legal insurance comparison and banking services as part of a cross-functional team. Implemented automated testing and supported the CI pipeline to enhance release quality and development speed.
Writing
Java · Spring Boot · AI
Using RAG with Java Spring Boot AI & Google Vertex AI: Crafting an Automated Resume Matcher
Read on dev.to ↗
Java · Docker · Kubernetes
From Prototype to Production - Local Kubernetes: Our AI Resume Matcher's Journey
Read on dev.to ↗
AI · Java · ADK
From RAG to Multi-Agent AI for Job Matching
Read on dev.to ↗
Kind Words
Tim was incredibly helpful in reviewing my software. His feedback was clear, constructive, and always spot-on. I really appreciated his support and expertise.
Oliver HommelWorking with Tim was a pleasure. I was always impressed by his technical skills, reliability, and collaborative spirit. He consistently delivered clean, thoughtful code and was a great team player. I’d jump at the chance to work together again.
Juri Zeisler