Kosta Yanev


Kosta Yanev is the inventor of Activbody’s exercise system and the company’s founder. Kosta is a nuclear physicist and holds a PhD in computer science. He has worked at CERN in Switzerland and has founded and launched numerous successful businesses including FTSAM (airport development), Great Bear (GTBR), Company for Energy Saving (JV with RWE – Germany), DONTNOD Entertainment (Paris), Shibuya Productions (Monaco) and now Activbody.

Reuben E. Katz

Chief Executive Officer

Reuben Katz is the CEO of Activbody, leading the company’s vision, culture, strategy and growth as he merges physical and mental activity into a data-driven world. 23 years of entrepreneurial experience began at 22 when he opened an ad agency in Philadelphia. In 1998 he launched, as Founder & CEO, the first online ‘Amazon in Spanish’ which sold in 2002. He has since founded and invested in companies in advertising and media, international distribution and publishing, B2C and B2B tech startups, social media networks, multiple childcare facilities and social good initiatives.

Reuben is creator of the social-good global #Hack4good initiative, uniting Non-Profits such as WWF, Save the Children and MSF Doctors without Borders, with developers, product managers and leading tech innovators to solve some of the world’s biggest problems. In 2011 Reuben founded and was CEO of venture-backed startup, Geeklist, the first social network for software engineers.

Reuben is currently a General Partner and LP in Raicap Venture Capital Fund, as well as an active angel investor and advisor in technology startups. In his spare time he is an avid polo player, helps his wife and daughter in their dog rescue missions in Baja California, and is involved in various charities.

Michael “Pyro” Floyd

Chief Operating Officer, Head of Product

Michael “Pyro” Floyd is a seasoned technology veteran with over 25 years of product development, management and operations experience. While at DivX he held various leadership roles including Vice President of Operations and Vice President of Engineering. He also served as the Vice President of Product Management for BitTorrent Inc. where he was responsible for product strategy and development of a suite of products with over 180 million users. Michael has both a Bachelor and Masters degree in Computer Science from SDSU as well as an MBA with a specialization in Globalization from USC.

In his spare time, ‘Pyro’ enjoys being a seasoned Pyrotechnician who has worked on more than 70 fireworks displays, he enjoys coaching Lego Robotics, backpacking and model rocketry.

Seth Cummings

Chief Marketing Officer

Seth Cummings has over 15 years of experience creating and building brands. He ran digital marketing for Boost Mobile (acquired by Nextel). He was co-founder and SVP at Amp’d Mobile and was EVP of Marketing and GM of Prepaid at Clearwire (Nasdaq: CLWR; acquired by Sprint). Most recently, he was EVP of Marketing at VoIP innovator magicJack VocalTec Ltd. (Nasdaq: CALL). He earned an MBA & MS in Television Management from Boston University.

Angel Vassilev

VP Product

Angel Vassilev is a co-inventor of ActivBody’s products and manages hardware development and supply chain. Prior to joining Activbody Angel spent 16 years in a variety of creative roles designing multimedia, video games, and airports. He helped found four companies (including Activbody) and is a trained architect.

Viktor Kalvachev

VP Creative

Viktor Kalvachev has over 20 years of creative and art direction experience across the entertainment industry. He has worked on projects for clients like Steven Spielberg, Disney, PIXAR, Big Fish and Nokia. Viktor received 2 Eisner nominations for his graphic novel Blue Estate. He holds an MFA from the National Academy of Fine Arts in Sofia, Bulgaria.

Ludmil Kalaydjiyski

Senior Director of Engineering & QA

Ludmil Kalaydjiyski has over 24 years of engineering experience working for ALSTOM UK, Motorola, Nokia Siemens Networks, Keysight Technologies, Anite Telecoms, and Activbody. He is responsible for Technical and QA supervision of the full product life cycle for the Activ5 Smart Strength Training Device: from requirements to production, all engineering, quality, process and test activities, including manufacturing stage, and management of US and EU device Certification. Ludmil also managed all test activities for iOS & Android Apps and games. He made design contributions to device security features.

Over six years, Ludmil participated actively in the design and testing throughout the Activ5 device and software product evolution as Technical Project Lead, Software and QA Manager. He played an active role in creation of product prototypes, like Corporate Wellness, submission of device-related patent applications, requirements, interface definitions, and multi-national distributed development. He owned the Agile process and performed product acceptance procedures.

Ludmil has a PhD in Computing and BEng degree in Automatic Control. He has experience in the telecommunications and power electronics industries, including mobile networks, RF & system testing, software development, and real-time systems. He has expertise in Rapid Application & Agile development, and ISO Quality audits.

Ludmil’s hobbies include weight training and swimming.

Kim Carson (Designer/Developer)


Kim Carson is a visual/UI/UX/interactive designer and front-end developer who executes the Activ5 creative vision. She brings more than 15 years of experience working for dozens of companies around the world designing, developing and shipping responsive websites and web applications, mobile apps and other digital media. While she’s not implementing cool effects, blowing out the latest promotional campaign, or figuring out how to make user experiences better, she’s studying politics, screaming her head off for the Seattle Seahawks, or trading cryptocurrencies.

Jan Zikmund

Senior Developer

Jan Zikmund was born on World Health Day. Accordingly, he’s adopted a love of sports and fitness, which keeps him fueled to develop Activbody’s online platform. Jan possesses all common web development skills – from cutting PSD to responsive retina friendly HTML, through Javascript to PHP development, setting-up WordPress and Magento websites and programming tailor-made functionalities. When he’s not coding, Jan can be found snowboarding, surfing, playing guitar, meeting people, learning languages and living life on his terms.