About Me
Born and raised in Belgium, I love working on hard problems. When I'm not coding, I'm likely riding my motorcycle, climbing or catching some waves!
Job
Currently I'm working as a software engineer for Apryse on the iText SDK and the related product suite. I’m also a member of the PDF Association, working to advance and improve the PDF specification.
Consulting
As one of the core developers on the iText SDK, I'm knowledgable about PDF's and document workflows. This includes but is not limited to:
- Document generation, modification
- PDF-UA, PDF-A compliance as required by the eu and US
- Html 2 Pdf Conversion
- Digital signing and signature validation
Technical blog posts
- 2025-08-13 Supporting apache xml in GraalVM
Projects
- How I Made PDF Table Rendering 95% Faster in an Afternoon – A blog about optimizing a key bottleneck in the table rendering engine.
- Html 2 well tagged pdf – One of the first implemenations in the world which is able to convert html to fully a fully valid WTPDF build on top off iText
Contact me!
Email: guust[dot]ysebie[at]gmail[dot]com
Whatsapp: +32 49 298 34 21
Github: Github profile
Linkedin: Linkedin profile