I grew up in Switzerland, studied Mathematics at ETH in Zürich, and got a Ph.D. in Computer Science from ETH in 1991. At that point I was already working for IBM Research in Switzerland. In November 1991 I moved over to IBM T.J Watson Research Center in the US. In June 2011 I moved to Melbourne, Australia, to build up a new Research lab for IBM, where I am still working today.
One of my favorite hobbies is woodworking, especially making wooden puzzles. I used make puzzles during my high school years, but then lapsed for a while. Mostly since I - initially - had no woodworking equipment in the US. That got fixed at some point when Karin wanted some special furniture for our house. While attending a woodworking show I found Jerry Slocum's book "Puzzles old and New" [Slocum86]. This led me to tinker around with 6-piece burrs and the creation of the burr puzzles site.
After my first year of studying Mathematics at the Federal Polytechnic Insitute in Zürich (ETHZ), I had to pause for a year of military service in the Swiss army. When I returned to the university to continue my math studies, I found out that a beautiful woman had started studying math during the year I was away.
A few years later we married.