#Hi, I'm Guust
I'm a software engineer born and raised in Belgium, and I love working on hard problems. When I'm not coding, I'm likely riding my motorcycle, climbing or catching some waves!
I work on the iText SDK and its related product suite at Apryse. I'm also a member of the PDF Association, working to advance and improve the PDF specification.
##What I work on
As one of the core developers of the iText SDK, I work across the whole PDF stack:
- Document generation and modification
- PDF/UA and PDF/A compliance, as required in the EU and the US
- HTML-to-PDF conversion
- Digital signing and signature validation
Want to talk PDF? Get in touch.
##Latest writing
- New EU Trusted Certificates Released
A blog post about the new EU Trusted Certificates that have been released and how to update LOTL validation feature with iText.
- Want to Make Your PDFs 20% Smaller for Free? ↗ pdfa.org
Adding experimental Brotli compression to Pdf and iText
- Supporting org.apache.xml.security in GraalVM
How to get org.apache.xml.security working in GraalVM native images.
##Talks
- Devoxx Belgium 2026: Engineering Lessons from Working on Software Older Than Me
- Microsoft Build 2026: Design systems for every user, including people and LLMs
- GIDS 2026 (India): Your Users Are Not Just Human: Designing Systems for People and LLMs
- PDF Days Europe 2025: Enterprise-Grade HTML 2 PDF, technical poster
All talks and speaking topics →
##In the press
- Computerworld, January 2026: New PDF compression filter will save space, need software updates. Quoted on getting the PDF ecosystem to adopt Brotli: "Somebody has to jump first and make some noise so other products jump on the bandwagon."
##Projects
Open-source work on Brotli compression for PDF, Well-Tagged PDF examples, and a Rust CLI for working across many repositories. See all projects →