Stol, who was previously a creative technologist at Remedy Six, will be responsible for ensuring Rapp is a leader in digital innovation.
Before Remedy Six, Stol was head of creative development at Harrison Troughton Wunderman. He has also worked at Video Networks and Sony Europe.
Rik Haslam, Rapp executive creative director, said: "Gedeon has been at the forefront of technology for many years and is working in the heart of Rapp's creative department, helping ensure we stay ahead of the game in the digital sphere and integrating our digital expertise into the agency as a whole."
Separately, the agency has hired a senior concept team, Tristan Fitzgerald and Simon Cheshire, from Saatchi & Saatchi Interactive. At Saatchis, Cheshire was head of interface design and Fitzgerald head of copy.
Andy Barker also joins Rapp as a senior designer from digital agency Maynard Malone, and Lindsay Keith has been hired as digital project manager. He was previously a digital strategy consultant at Canvass Consultants.
These hires follow last month's appointment of former Agency.com managing director Russell Marsh to the new role of group digital strategy director.