Since 2003, he has been the founder and CEO of Sheriff, a holding company for security companies. During this time Sheriff has become one of the most famous and reputable companies in the security industry of the country, has received a number of awards and was acknowledged by the mayor of Kyiv. In 2014, the holding's team was recognised as the winner of the All-Ukrainian Rating of Professionalism of Security Services. During 2017-2020. "Sheriff" received "Choice of the Year" awards by public vote. In 2021 he initiated the process of establishing an Advisory Board in the company.
He takes an active public position. During 2015-2019 D. Strizhov was the Deputy of Kyiv City Council of VIII convocation, member of the permanent commission on education, science, family, youth and sports. Since 2012, he has been a member of the board of the Public Organisation for the Protection of Human Rights. Since 2012 - Vice President of Ukrainian Pankration Federation, since 2013 - a member of the Executive Committee of Sport Committee of Ukraine, since 2018 - President of WPC World Pankration Council.
Education

• Artillery Military Institute in Sumy (1998)
• Kyiv Polytechnic Institute (2002), specialization: management of organizations, qualification: economist of production sphere.
• National Academy of Public Administration under the President of Ukraine (2012), specialisation: public administration in the sphere of national security, qualification: Master of Public Administration with honours.