David's professional career began in 2012 when he enrolled in military school. After graduating, he continued his higher education in security and law enforcement. During his studies and beyond, he actively engaged in self-education in shooting tactics and security issues. He led a youth shooting group for several years. David has nearly ten years of experience in security forces, serving as a first-line patrol member and a training instructor for the Czech Police. Over the years, David participated in numerous courses, including those from organizations such as Hard Task, Elite Lhenice, ESP, ASP-Instructor, GTac, the Czech Police, and the Czech Army. He has also collaborated on operations with the Ministry of Defense's Special Operations Command (SOC MO), foreign Special Operations Forces (SOF), and has contributed several times to training Poland's Border Guard at the Szkoleń Specjalistycznych SG.