Senior Fullstack Software Engineer

I am a freelance Senior Fullstack Software Engineer with over 25 years of experience building production-grade SaaS and platform systems. My focus is clean architecture, reliable backends, and consistent server-side authorization and access control (RBAC, entitlements, audit logs)—including financial and regulated domains. Tech stack: React, Next.js, TypeScript, Node.js, PostgreSQL.

When needed, I integrate GDPR-compliant AI/LLM functionality with OpenAI or Azure OpenAI (EU).

Available for remote engagements across Europe · Production-grade SaaS · Clean Architecture · Server-side authorization

Request project

Consulting & Development

Frontend & Fullstack: React, Next.js, TypeScript, Node.js, REST, GraphQL
AI/LLM Integration (GDPR-ready): OpenAI / Azure OpenAI (EU), Retrieval-Augmented Generation
Vector Search & Data: PostgreSQL + pgvector, Prisma, ingestion for PDFs/SharePoint/CRMs
Security & Compliance: Auth.js/OAuth2, RBAC, audit logs, token usage analytics
DevOps & Deployment: Docker, CI/CD (GitHub Actions, GitLab), Vercel, Cloud integration

AI Integration & Knowledge Systems

Design and implementation of LLM-powered applications with vector search, structured prompt design, token accounting, and GDPR-compliant server architecture.
Focus on controlled server-side orchestration, cost transparency, and secure integration into existing platforms.

Selected Projects

AI-powered Intranet Platform (TÜV Rheinland)

Platform for managing AI-powered chatbots with document uploads, vector search, and streaming chat.
Integrated OpenAI/Azure OpenAI (EU), DeepSeek, and DALL·E.
Token accounting with tiktoken, GDPR-compliant logging, and server-side orchestration.
Stack: React, Next.js, TypeScript, Node.js, PostgreSQL (pgvector), Prisma.

Valutra – Personal Financial Planning App

Production-grade financial forecasting SaaS with deterministic, rule-based multi-year cash-flow simulation. Built end-to-end (UI, API, data model, deployment) with strict server-side enforcement of roles, entitlements, and limits.

Deterministic multi-year cash-flow simulation
Strict server-side entitlement enforcement
WCAG 2.2 AA compliant architecture

View Valutra live → Technical details

MediaMarkt/Saturn – GDPR Consent & Tracking

Implemented GDPR-compliant consent layers for e-commerce shops, built a server-side tracking pipeline, maintained legacy pages via a standalone library (GTM). Stack: React, TypeScript, Node.js, Styled Components, GraphQL.

Language Learning Platform (Learnship/XaaSify)

Built an HTML5-based language learning platform with WebRTC, multi-tier microservices backend (Scala/Akka/Kafka/Cassandra), and React/TypeScript frontend. Focused on reliability and scalability.

Additional references (2000–2016) mostly in the banking & logistics sector using Java/JEE/Spring, SOAP/REST, Oracle, JSF/Struts – details on request.