Hello, I'm Henny Krijnen

As the Lead Developer at eWarehousing Solutions, I'm responsible for the full technical stack of our Warehouse Management System. I migrated our infrastructure to Kubernetes with Terraform, enabling us to rapidly spin up isolated WMS instances, even through a form-based POC. I modernized our backend by upgrading Symfony from 2.8 to 6.4 and integrated Roadrunner to speed up PHP responses. I built queue-driven async document generation, client webhooks, and a middleware proxy layer. I authored all documentation in Markdown/MDX, improved performance through query tuning and business logic design, and created a yearly 'Wrapped' using Remotion. We also built seamless integrations with Sendcloud, Paazl, and Wolfpack.

As Krijnen development, I take on freelance work based on demand. Clients come to me with a challenge, I build the solution. I've developed data scrapers, dashboards, browser extensions, and cloud-based tools, often combining GCP services like Cloud Functions with containerized infrastructure. Everything I deploy runs on Kubernetes, provisioned through Terraform. Some clients hire me for small fixes, others for complex systems. I'm not on a fixed weekly schedule, but I'm available when the work requires it.

At Telefuture Direct, I developed a Symfony tool that integrated with Sanity.io via REST to enable translation workflows using XLIFF. This allowed content creators to manage their articles centrally while easily collaborating with external translators. I also built a dedicated Symfony frontend that consumed Sanity content and rendered localized pages. Additionally, I created a dynamic landing page theming system where designers could define visual layouts through JSON files, streamlining the campaign setup process. I also began introducing Docker to the development stack to improve consistency and reduce onboarding friction.

At Notive, I started as a junior developer and worked my way up to lead developer. I worked across a wide range of technologies including PHP (Symfony), Python (Django), Go, and Java. A large part of my role involved developing e-commerce integrations with platforms like WooCommerce, Magento, Shopify, and Lightspeed for clients such as Klarna, Heineken, OK Betalen, and eWarehousing. I was responsible for writing plugins, building middleware, and working directly with clients through meetings, sprint planning, and support. I gained valuable experience with Docker, Docker Compose, Linux environments, and deploying services to both VPS and Kubernetes clusters. These years taught me how to build reliable systems and how to communicate technical concepts effectively with both clients and teammates.

This was my first real web development job, and it was a great learning experience. I built a lot of websites using Joomla CMS and created custom modules when we needed something specific. One of the more interesting projects was building PHP web crawlers to collect data for our clients. It was my first exposure to working with APIs and handling large amounts of data. Looking back, this job really helped me understand the basics of web development and database management.

This job was all about helping people with their tech problems. I'd go to people's homes or small businesses to fix their computers, set up networks, or teach them how to use their software. It was really rewarding to help people who weren't tech-savvy understand and use technology better. I learned how to explain technical things in simple terms, which has been useful throughout my career. It was also great experience in problem-solving and customer service.