When I was about 8 I started out in BASIC on my dads 80286 PC. Soon BASIC wasn't powerful enough anymore and I switched to Assembly. After a couple of years I switched to C/C++ which has been my 'weapon of choice' ever since.
During college, most of my time was spent on creating games. Tank Arena and Blaster Disaster were the results of that.
After getting my masters in Physics, I started working for a company called Lost Boys Interactive in Amsterdam. They mostly created interactive CD-ROM applications. During that time I made a couple of PC games: Game Hits 3D and Grachten Racer.
When the games division of Lost Boys (now called Guerrilla Games) needed some extra hands for a couple of weeks to produce a demo for Sony, I jumped in.
The demo turned into the PS2 game called Killzone and about half way through the project Shellshock Nam '67 was started. I became the lead programmer of that project. The game was released on XBOX, PS2 and PC.
After both Killzone and Shellshock were finished, Guerrilla Games was bought by Sony and we started working on two new games. One game was for PSP and called Killzone Liberation, and during the pre production period I led the game programming team. After that I moved on to Killzone 2 and Killzone 3.
After Killzone 3 I decided that it was time to spend some more time doing technical designs and programming so we split up the game team into a Game Feature and a Game Tech team (the Game Tech team being responsible for more low level / reusable systems, the Game Feature team being responsible for creating the actual gameplay). I became lead on the Game Tech team. I then worked on Killzone Shadow Fall, Horizon Zero Dawn and Horizon Forbidden West.
In my spare time I always enjoyed writing little games. I made the game SjoelIt in C# and I made the game Islands: Missile Invasion to learn J2ME. I worked on Online Frontlines to try out Java/Flash. Next to this I also worked on Monster Crush to see what iPhone development is all about.
Next to programming I like to hike, swim, and cycle.