Who I am – German citizen with unrestricted work and residence permit in Brazil. Architect, Modernizer, Consultant - Senior software engineer with 20+ years of experience in full-stack web development and recent specialization in modern SAP full-stack development, including SAP BTP, S/4HANA modernization, ABAP, CDS, OData, Fiori/UI5 and API integration. Based in Brazil with family,
available internationally for remote-first consulting and project work.
On the 'web side': I’ve spent many years building and running Drupal sites, React Web applications, handling migrations, performance tuning and technical SEO/GEO to keep organic traffic and conversions stable during change.
I’m an engineer and architect who enjoys untangling systems that have grown for years and turning them back into something a team can work with.
That happens in two worlds. In SAP, where heavily customized landscapes need to become clean‑core and upgradeable. And on the web, where grown PHP and JavaScript platforms carry the same kind of debt. I clarify the real problem, design a realistic target picture, and modernize code, interfaces and UIs step by step — in slices that can each go live.
I work with companies whose software still runs, but has become expensive to change. That happens in SAP landscapes with twenty years of custom code, and it happens just as much in a PHP platform that nobody has maintained for five years. The technology differs, the problem does not.
My background: 20+ years in web and enterprise development, with the recent years split between ABAP Objects, CDS, OData, SAP BTP and Fiori on one side, and PHP, React, TypeScript, Node.js and REST APIs on the other.
If any of the following sounds familiar, we probably have something to talk about:
Legacy code debt
Too much grown custom code, poorly documented and hard to test. Every change takes longer than the estimate, and nobody can say for sure what a given report actually does.
Nobody knows the system any more
The developers who built it have left, there is no documentation, and the business rules only exist inside the code. This is where AI-assisted analysis plus disciplined verification saves the most time.
Upgrade and migration risk
Business-critical custom code that makes every upgrade, support package or platform move a risk. Moving that code into clean, upgrade-safe structures takes the risk out of the calendar.
Integration spaghetti
Point-to-point connections, old RFC and BAPI calls, undocumented interfaces between shops, partners and internal systems. I replace them with documented API-driven integration that works across on-premise and cloud.
Business processes that quietly broke
Availability that is wrong, bookings that do not arrive, orders that need a manual fix every day. Usually a symptom of the points above, and usually the reason someone finally calls.
Delivery pressure
Pressure from the business to deliver new features faster, without breaking what already works. That is a sequencing problem, and it can be planned.
My work has two roots. Twenty years of web engineering, fifteen of them inside a holiday-rental agency, and four years of SAP development in industrial projects. Both sides deal with the same thing: systems that have grown for a long time and now need to change without breaking.
These are the five areas I take on. They overlap more than they look, because the method behind them is always the same: understand what is really there, write it down, then rebuild it in steps that can each go live.
SAP development on S/4HANA and BTP
Custom applications and extensions built the way SAP intends them today: business logic in object-oriented ABAP, data exposed through CDS and OData, RAP in the stack, CAP and Node.js side-by-side on BTP, and Fiori or UI5 on top. Extensions go into the layer they belong in, so the core stays close to standard and upgrades stay boring.
ABAP custom code refactoring
Reports, Dynpro applications and Z developments that have been extended for twenty years and are no longer safe to touch. I read the code, reconstruct the business rules, agree them with the people who use the application, and then rebuild it in ABAP Objects with separated layers and modern ABAP SQL. In slices, each one releasable on its own.
AI-assisted modernization of legacy applications
The analysis phase is what usually makes legacy projects unaffordable. AI-assisted code reading gives me a first map of an unknown system in days instead of months, and every finding is then verified against the running system before anyone acts on it. I use this daily in two productive environments right now, one SAP and one PHP.
Travel and booking platforms
Availability and inventory logic, enquiry and booking workflows, property and partner data, seasonal pricing, and the interfaces between all of them. I spent fifteen years inside a holiday-rental agency and I am back in that platform today, so I know the domain from the business side, not only from the code.
Full-stack web development
React and TypeScript on the frontend, PHP or Node.js and REST APIs behind it, relational data models underneath, and the Linux or cloud infrastructure it all runs on. Most of this work is modernization: taking over an existing codebase, making it maintainable, and writing the documentation that was never there.
I think and work like an architect, not only like a developer: a clear target picture, a step-by-step roadmap, and honest trade-offs instead of one more quick enhancement. I speak the language of business and of IT, and I am used to turning vague modernization goals into concrete work packages.
What makes the profile unusual is the combination. There are many strong ABAP developers and many strong web engineers. Few people work in both worlds at the same time, and that is exactly where most modernization projects get stuck.
Architect
I create a clear blueprint: where you are, where you want to go, and which steps get you there with acceptable risk and budget. No big bang, but realistic, incremental modernization.
Modernization expert
I enjoy brownfield landscapes with technical debt. I can read old code, talk to the people who built it, and turn that into cleaner, testable solutions that respect what you have already paid for.
AI-assisted, but verified
I use AI to read and summarize unknown code, which shortens the analysis phase considerably. I do not use it as a source of truth. Every finding is checked against the running system before it goes into a decision, and I will tell you where the method has limits.
Two worlds, one method
SAP and the open web. ABAP Objects, CDS and BTP on one side, React, TypeScript, Node.js and PHP on the other. That means I can design an integration end to end instead of handing it over at the system boundary.
Domain knowledge, not only code
Fifteen years in a holiday-rental agency and four years in industrial SAP projects. I have sat on the business side of these processes, which shortens a lot of requirement discussions.
Consultant
I do not only deliver code. I explain options and trade-offs in a way decision-makers understand: what has to stay in the core, what should move out, and what should simply be retired.
One CV that covers all five areas would be a CV that says nothing. So there is a separate version per focus area, each with the same facts but a different emphasis, and each in an employee and a contractor variant.
All of them are three to four pages, in English, and include the reference letters and certificates. If you need a German version or a specific format, just ask.
SAP development on S/4HANA and BTP
ABAP Objects, CDS, OData, RAP, CAP, Fiori and UI5, with the SAP project list included.
ABAP custom code refactoring
Grown Z code and Dynpro applications rebuilt in ABAP Objects, R/3 to S/4HANA, Clean Core.
AI-assisted legacy modernization
Undocumented systems in ABAP and PHP, including how the analysis method actually works.
Travel and booking platforms
Availability and inventory logic, booking workflows, travel APIs, twenty years in the domain.
Full-stack web development
React, TypeScript, Node.js, PHP and REST APIs, with enterprise integration from the SAP years.
All of my skills are self-taught, built through deliberate learning and proven in real-world practice. I don’t just collect tools – I design my own learning paths, break complex topics into concrete experiments, and keep what works. I only adopt approaches and technologies that prove genuinely useful in practice, so what you see here is what has actually helped to build and run real systems.
German citizen with unrestricted work and residence permit in Brazil. Senior software engineer with 20+ years of experience in full-stack web development and recent specialization in modern SAP full-stack development, including SAP BTP, S/4HANA modernization, ABAP, CDS, OData, Fiori/UI5, and API integration.
Focused on scalable business applications, Knowledge of clean architecture and SOLID principles.
Lead technical modernization and digital transformation of a multi-site vacation rental platform based on Drupal.
Designed a modernization roadmap for a legacy Drupal platform architecture, including API-driven integrations and service-oriented design, cloud-based infrastructure strategy, developed API-driven integrations and supported digitalization initiatives across booking, content and operational workflows.
SAP development role focused on modernization and integration in S/4HANA-related projects. Improved backend API interfaces in an S/4HANA project to increase integration readiness and maintainability, supported productive web services during hypercare in the FI environment and refactored a SAP Business Suite Dynpro application into object-oriented ABAP for better maintainability and future S/4HANA compatibility in an IS-U context.
Worked closely with business stakeholders, solution managers and developers to align implementation with functional requirements.
SAP consulting and development with focus on ABAP, UI5, Fiori, S/4HANA, SAP BTP and modern extension models.
Developed and enhanced SAP applications using ABAP, CDS, OData and UI5, contributed to ERP-to-S/4HANA migration projects, refactored existing applications and worked on side-by-side and developer extensibility scenarios in S/4HANA Public Cloud.
Full-stack development in an Industry 4.0 environment with React frontends, PHP backends, API integration and Linux-based infrastructure.
Successfully converted an outdated PHP web application to a modern PHP REST backend and connected it to a newly created React web frontend including database modelling.
Long-term responsibility for full-stack web development, operations, optimization and technical infrastructure.
Developed and maintained websites and web applications with PHP, Drupal, HTML and CSS, managed Linux and network environments and improved traffic, performance and usability through technical SEO and usability-focused optimization.
Intensive, practice‑oriented software architecture 5‑day training based on the iSAQB CPSA‑F curriculum. Covered fundamentals of software architecture, architectural styles and patterns, quality attributes, documentation, and communication with stakeholders. Included exercises on modularization, domain‑driven design, and designing scalable, maintainable systems in heterogeneous environments such as cloud, web, and enterprise platforms.
iSAQB CPSA-F Foundation Level training completed; exam planned for Q4/2026
Intensive agile project management (Scrum) training at Indisoft GmbH (Leipzig) with focus on Scrum and Kanban (05/2020–06/2020). Covered Scrum roles, events, and artifacts, agile planning and scaling, Scrum simulations in practice, and Kanban principles such as WIP limits and continuous improvement. Successfully completed the program and obtained the Professional Scrum Master I (PSM I) certification from Scrum.org on June 8, 2020.
One‑year, practice‑oriented Full‑Stack Web Developer program in Leipzig (01/2020–01/2021) covering modern web development with HTML5, CSS3, JavaScript, jQuery/AJAX, PHP, and MySQL, combined with Linux/server administration and content‑management systems. The curriculum included responsive web design, WordPress and TYPO3 for developers, e‑commerce and shop systems, SEO/SEA, social media marketing, and project work, linking technical implementation with online visibility and performance optimization. The training built directly on and further professionalized my long‑term experience as a webmaster and Drupal/PHP full‑stack developer for fincaferien.de, including topics such as technical SEO, usability, and scalable web architectures.
Two‑year vocational apprenticeship as an Industrial Clerk in Hildesheim, providing a solid foundation in business processes, commercial management, and office administration. The program covered fundamentals such as accounting, cost and performance calculation, procurement, order processing, and customer communication, giving me a practical understanding of how companies operate and make decisions. This early business education has shaped my entire career by enabling me to connect technical solutions with real commercial requirements and organizational structures.
Ways to contact me