Heiko H. - Fullstack Developer / Architect

Petershagen, Germany

Experience

May 2025 - Jul 2025

3 months

Germany

Design and implementation of a solution to manage projects, materials and assets in field operations.
Allows project managers to track inventory, plan requirements and issue transport and order requests via a modern web application (Blazor).
Field staff use a mobile MAUI app for stocking and destocking materials, supplemented with location-based photo documentation in map views.
Control of all business logic through a central API.
Tech stack: .NET 9, PostgreSQL, Docker, Docker Compose, Ansible, Keycloak, Aspire.

Jan 2025 - Aug 2025

8 months

Germany

Created small sample apps with React, .NET MAUI and Microsoft Aspire to evaluate modern cross-platform and cloud development approaches.
Learning projects on infrastructure-as-code and orchestration with Terraform, Ansible and Kubernetes (locally and in the cloud).
Developed a C# .NET 9 prototype for outdoor warehouse management with Keycloak authentication and Aspire integration.
Implemented a C#-based AI tool server with integration into Open WebUI.
Experiments with n8n for workflow automation.

May 2023 - Nov 2024

1 year 7 months

Germany

Complete redesign of the codebase and user interface of a multi-user WPF application for automated programming of tamper-proof fiscal data sticks with integrated SLE module.
Management of the entire production process from license number handling through PKI-based certificate creation to delivery of firmware and configuration data on microSD cards.
Real-time monitoring of central services (number reservation, PKI) with automatic failover to redundant servers and status indicators to avoid production interruptions.
Signing of all relevant fiscal data in the SLE module to ensure integrity and tamper protection.
Coordinated a developer team, implemented security-critical cryptography and production processes, and wrote unit tests.

Mar 2019 - Dec 2022

3 years 10 months

Germany

Designed and further developed a cross-country microservice architecture for controlling and monitoring wind turbine fleets in European control rooms.
Processed real-time status information and integrated manufacturer-specific interfaces into a scalable system landscape.
Designed and implemented a modular command agent for centralized remote control and power regulation of entire wind farms.
Developed a configuration software for flexible adaptation to different manufacturer protocols.
Successfully moved into production with a view to licensing and international market expansion.

Jun 2018 - Dec 2018

7 months

Germany

Developed a central service for automated generation and distribution of network configurations for a nationwide branch network in Germany.
Converted legacy mainframe data structures into maintainable C# logic.
Migrated and processed configuration data on Microsoft SQL Server to generate standardized network scripts and automated rollout.
Technical design, quality assurance and setup of automated tests.

Nov 2017 - Jun 2018

8 months

Germany

Further development of a model-driven commercial software solution for municipal utilities and energy suppliers.
Implementation of a graphical modeling interface to define workflows, information flows, dialogs, and business logic.
Coverage of the entire process area from market communication via EDIFACT message exchange to tariff design and invoicing.
Development of new features in the frontend and backend, as well as automated tests for quality assurance.

Sep 2010 - Aug 2015

5 years

Germany

Development of a base framework for lab devices for molecular and immunological diagnostics, including core functions like logging, settings, security, and database migration.
Conducting feasibility studies for new technologies (e.g., Entity Framework).
Setting up and maintaining automated integration and UI tests with full traceability to requirements and specifications according to IEC 62304.
Participation in risk assessments and quality assurance measures.
Introduction and further development of agile practices as a Scrum Master in an international team environment.