Tech Lead. Senior Engineer.
Hamburg.

A platform for a business group with 1,700 employees (European market leader in PVC window profiles) — connecting architects and planners directly with manufacturers of window and door systems. Designed and implemented AI-driven analysis of tender specifications via the OpenAI API as the basis for auto-filling quote forms. Internationalisation for rollout into further European markets (Croatia, Romania). Direct technical coordination with the client's IT department as the interface between the project team and client infrastructure.

OutcomeLive with over 100 active users and more than 5,000 tendered line items.

• Next.js
• TypeScript
• Prisma
• MS SQL
• OpenAI API
• Tailwind
• Cypress
• React Hook Form
• Jest
• GitLab CI/CD
• Sentry
• Google Maps

A central application for a mid-sized business group — site planning, team overview, work packages and equipment management, offline-capable on site with deferred sync. Integration into accounting and order management via Node.js microservices; high-availability architecture with A/B cluster setup.

Outcome€300,000 annual savings from reduced planning effort + €240,000 in eliminated licence costs — across 70 site managers. App now run entirely in-house.

• React
• TypeScript
• Ruby on Rails
• PostgreSQL
• TanStack Query
• PWA
• Node.js

A high-availability platform for exchanging critical warning messages between civil-protection authorities — nationwide reach, dozens of connected sites. Satellite-based fallback channel (~2.4 kbps) for network-independent communication during infrastructure outages. Integration of physical warning infrastructure: sirens and optical warning signals.

OutcomeDeployed nationwide. The team grew from 5 to 11 engineers over the engagement.

• Java
• Spring Boot
• Angular
• MongoDB
• Docker
• Kubernetes
• Terraform

Replaced a macro-based Excel solution at a Hamburg media agency with a modern web application — iterative migration with the legacy system in parallel. Focus: reverse-engineering the business logic buried in Excel macros and formulas, separating genuine requirements from historical workarounds.

OutcomeLater spun out as an independent GmbH.

• Ruby on Rails
• React
• Marionette
• Docker

Long-term engagement with the same client across multiple project phases: first, containerising and modernising the deployment infrastructure — from manual VM deployments with 2+ hours of downtime to Docker Swarm with near-zero-downtime deployments. Later, incrementally migrating the legacy Rails/jQuery application to a modern React SPA — without disrupting ongoing productivity.

OutcomeDeployment downtime reduced from 2+ hours to near zero. Multi-year client relationship sustained through successful, non-disruptive modernisation in live operation.

• Ruby on Rails
• React
• Spring Boot
• Apache Solr
• PostgreSQL
• MariaDB
• Redis
• Docker Swarm
• Ansible
• Terraform
• GitLab CI

A highly optimised network-traffic analyser (nfcap data from around ten German university sites, >100 MB/min) for early DoS detection via statistical anomaly detection. Plus safety-critical communications systems: encrypted mailing-list software and high-availability data exchange for security officers.

• Python
• Django
• PostgreSQL
• Linux