References
Projects delivered, with what they were made of.
A selection from 25 years — the ones where the architecture decisions were mine to make. The full history, including the early years, is in the CV.
Reynt — multi-tenant rental & booking platform
A production, GDPR-compliant multi-tenant SaaS made in the EU. Thirteen packages, roughly 480,000 lines and 3,800+ commits in about eleven months, covered by ~1,400 tests: four Hono APIs, three Nuxt 4 frontends, an Astro marketing and docs site, a headless SDK. Tenant isolation by construction through PostgreSQL row-level security; PII encrypted at rest per tenant, searchable via blind indexes and erasable by crypto-shredding. Domains span the booking lifecycle, multi-option offers, an append-only payment ledger over Stripe Connect and PayPal, invoices and settlements, pricing and availability, a CMS storefront builder, localized multi-language SEO, and local tax and registration compliance. Product AI features include a tool-calling agent behind an operator approval workflow, an MCP server, and RAG-backed in-app help.
- TypeScript
- Bun
- Hono
- Nuxt 4
- Astro
- PostgreSQL (RLS)
- Drizzle ORM
- Stripe Connect
- Kubernetes
- MCP
MUSES — school IT platform for school authorities
A cross-state DigitalPakt project for Baden-Württemberg, North Rhine-Westphalia and Saxony: one interface through which school authorities and school IT staff manage WiFi access, support tickets, devices and content filtering. A .NET 9 backend on Clean Architecture consolidates five external SaaS services — Cisco Meraki, OTOBO, Relution, Cisco Umbrella and Keycloak — behind a single REST API; a React 19 SPA provides OIDC authentication and role-based access, alongside an accessible React Aria component library shipped as an npm package. A dedicated Rust service persists ticket requests ahead of the call and retries them with backoff, so nothing is lost during OTOBO outages. Operated GitOps-style on Kubernetes at a German host.
- C#
- .NET 9
- MediatR (CQRS)
- React 19
- Next.js
- React Aria
- Rust
- Keycloak
- Kubernetes
- FluxCD
- Terraform
Smartflow AI — workflow automation platform
Architecture and development of the backend for an AI-powered workflow automation platform.
- Kotlin
- KTOR
- TypeScript
- Python
- TensorFlow
- RabbitMQ
- PostgreSQL
Web3 NFT store & trading platform
Architecture and development of an NFT trading platform — frontend, backend and smart contracts on Polygon.
- Solidity
- Polygon
- Kotlin
- KTOR
- TypeScript
- React
- MongoDB
Allsky — monitoring of objects in the night sky
A platform for automated detection and monitoring of celestial objects using camera systems and ML-based image analysis.
- TypeScript
- Vue.js
- Kotlin
- Python
- TensorFlow
- OpenCV
- MQTT
- Flutter
Education management system for the public sector
Code and architecture reviews, recommendations and developer support.
- TypeScript
- Node.js
- Vue.js
- GraphQL
- Elasticsearch
- PostgreSQL
Monitoring web application for 3D printers
Architecture and development of frontend and backend, plus the shared libraries and tool stack behind them.
- TypeScript
- Angular
- ngrx
- GraphQL
- Node.js
- Elasticsearch
- PostgreSQL
Frontend tool stack & component library
Frontend technology concepts, interface definitions, and the libraries, tool stack and build tooling used across client projects — with developer support alongside.
- TypeScript
- Angular
- VCL / ng-vcl
- rxjs / ngrx
- webpack
- GraphQL
Want the references that come with a phone number?
Named contacts at former clients are available on request — as is the full CV with the complete project history.