Want to get in touch? Then drop me a message at matthias@mvalvekens.be.

I'm most comfortable in Python (3.x), Java (1.7+) and Scala (2.12+). I've also worked with Haskell and Javascript. I learned the ropes fiddling around with calculators, which has left me with a fairly solid foundation in Zilog Z80 assembly — abstraction, what's that?

Jokes aside, I'm a big fan of the functional programming philosophy in general, and the way I approach problems in software development tends to reflect that. That said, I'm always happy to try new things and expand my toolbox.

Tinkering with software is my hobby: my trusty Raspberry Pi performs all sorts of useful and less-useful automation tasks, and I've got more silly project ideas than I'll ever have time to implement. This has made me a firm believer in the power of open source tooling and open standards to promote innovation.

Here's a non-exhaustive list of other, more specific tools I've used so far:

• pyHanko

  Sign PDFs using Python. Includes support for PKCS11 devices in general, and the Belgian eID in particular. PyHanko also deals with all baseline PAdES profiles. This project is currently in alpha, but is already being used in production workflows by quite a few organisations, including some companies operating in the trust services sector.

• certomancer

  Quickly construct, mock and deploy PKI test configurations using simple, declarative YAML config. Includes integrated CRL, OCSP and time stamping service provisioning. Certomancer provides a standalone WSGI application with minimal setup requirements, and also integrates with requests-mock. This tool is heavily used in pyHanko’s test suite.

• django-double-entry

  Django reusable app to provide support for basic double-entry bookkeeping in the Django ORM. It also implements a highly customisable transaction processing API. The code is well-tested and has been running in production systems for about two years now.

• django-partial-state

  Support for transparent handling of incomplete objects in the Django ORM.

• Boggle

  A fairly basic Boggle clone with a Bulma-based user interface and a server running on top of Flask. Communication between client and server happens through a very simple JSON API. Goal: provide some responsible family entertainment during the coronavirus crisis.
  This project is no longer actively maintained.

Research articles

1. D. Kyed, S. Raum, S. Vaes, and M. Valvekens, L²-Betti numbers of rigid C^*-tensor categories and discrete quantum groups, Analysis & PDE 10 (2017), no. 7, 1757–1791. arXiv:1701.06447
2. S. Vaes and M. Valvekens, Property (T) discrete quantum groups and subfactors with triangle presentations, Advances in Mathematics 345 (2019), 382–428. arXiv:1804.04006
3. M. Valvekens, L²-Betti numbers of rigid C^*-tensor categories associated with totally disconnected groups, International Mathematics Research Notices 2022 (2022), no. 14, 10704–10766. arXiv:2001.10757

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PhD thesis

M. Valvekens, L²-Betti numbers for subfactors and rigid C^*-tensor categories, KU Leuven (2020).

Full PhD dissertation text (PDF)
Source code for the algorithms discussed in the appendix can be made available upon request.

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Other

M. Valvekens, Some remarks on free products of rigid C^*-2-categories, expository note (2020). arXiv:2008.12994

Mathematical colleagues

• prof. Stefaan Vaes, my PhD advisor at KU Leuven
• dr. Jonas Wahl, one of my office mates at KU Leuven, now at the Hausdorff Center of Mathematics in Bonn
• dr. Tobe Deprez, one of my office mates at KU Leuven, now working in machine learning research
• prof. David Kyed, professor at SDU and one of my co-authors
• prof. Sven Raum, professor at Stockholm University and one of my co-authors

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Industry links

• Centrica Business Solutions, my current employer
• iText Software, my previous employer
• ISO/TC 171/SC 2, the ISO committee responsible for various PDF-related standards, of which I am a member as part of the Belgian delegation (also on GitHub)
• PDF Association, the industry consortium that (among many other functions) directs most of the day-to-day standardisation activity in PDF-land

I speak Dutch, English, Japanese and French, and I'm involved with several choirs in and around Leuven.