About.
The person behind the code — background, experience, and what drives the work.
André Versteeg
Freelance Sitecore & .NET Developer
Zevenhuizen, Netherlands
Background
I'm a freelance developer with 24 years of experience building enterprise web applications for healthcare, insurance, and professional services organizations. My core expertise is in Sitecore XM/XP, .NET Core, and Azure DevOps — specializing in platform modernization and cloud migrations.
My professional journey started in 2000 with ASP.NET Web Forms, but my fascination with software began much earlier on a Commodore 64. I've been through the complete evolution of the .NET ecosystem — from Web Forms to MVC to .NET 9 — and witnessed Sitecore's transformation from traditional MVC to headless architectures with JSS and XM Cloud.
What drives me is building maintainable systems with clean architecture. I believe in proper CI/CD pipelines, comprehensive testing, and infrastructure as code. I'm passionate about Docker and Traefik for local development, Python for rapid prototyping, and AI-assisted development workflows. This entire portfolio site was built in a single day using Claude Code.
I'm a strong advocate for Scrum and continuous improvement. I love Docker, enjoy working with both large and small teams, and I'm not afraid to voice my opinion in retrospectives. Outside of work, I live in Zevenhuizen with my family of four and spend my spare time tinkering with a CNC machine, cutting wood and carving complex shapes.
Career Journey
Senior Sitecore Developer
CZ (Healthcare)
Sitecore XM 10.4 modernization project. Led .NET 8→9 migration with zero downtime, integrated GraphQL navigation and Blue Billywig video platform, mentored junior developers.
Technical Lead
De Goudse Verzekeringen (Insurance)
Technical leadership role including PR reviews, architectural decisions, and disaster recovery planning. Supported Sitecore XP→XM Cloud migration. Reduced RTO from 24h to 2h.
Sitecore Developer
Brunel (Professional Services)
Sitecore 10 JSS headless implementation for MyBrunel platform. Azure DevOps pipelines, Helix architecture, and automated publishing workflows.
Sitecore Developer
Eneco (Energy Sector)
Headless JSS proof of concept for Eneco's customer portal. Process improvements and technical documentation for development team.
Senior Sitecore Developer
AON (Professional Services)
Built greenfield Sitecore JSS 9.1 + Vue.js/Nuxt.js platform from scratch. Launched 8 country sites in 6 months with Helix architecture, GraphQL API, and full CI/CD automation.
Full-Stack .NET Developer
Gengu (E-commerce)
ASP.NET MVC development for e-commerce platforms. First professional exposure to Sitecore CMS. Learned clean architecture patterns and dependency injection.
Started Professional Career
Triangle Networks
First professional role as web developer. Built websites and applications using ASP.NET Web Forms, HTML, CSS, JavaScript, and C#. Foundation of 24-year career.
Certifications
24+ Years Professional Experience
Self-Taught
2000
Sitecore XM/XP Specialist (Versions 7-10.4)
Practical Expertise
2015-2025
Azure DevOps & Infrastructure
Practical Expertise
2018-2025
Let's work together
Looking for a developer who cares about quality as much as deadlines? I'd love to hear about your project.