the software that generated the slides is called Beamer https://en.wikipedia.org/wiki/Beamer_(LaTeX)
- he works in Germany (https://vedran.miletic.net/files/cv-vedran-miletic.pdf)
- the original author is Till Tantau (https://www.beamer.plus/Introduction.html) who is German (https://www.tcs.uni-luebeck.de/en/mitarbeiter/tantau/cv/)