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Our Leaders

Larry Kestelman


Larry is the founder and director of Oxygen Ventures, and a lead investor in Saisei. Larry brings with him an extraordinary wealth of knowledge and experience in business development. A serial entrepreneur, Larry is best known for founding Australian-based telecommunications and utilities provider, Dodo, which he exited for circa $250M in 2013. A seasoned property developer, Larry is currently constructing Melbourne’s largest residential and commercial development outside the CBD, Capitol Grand (a circa $500M development) as part of his LK Property Group. Larry’s other business ventures include Acquire BPO with over 7,000 employees in contact centers across Australia, the Philippines and the Dominican Republic, as well being owner of Australia’s National Basketball League and the Melbourne United Basketball Club.

Boris Rozenvasser

Executive Director

Prior to joining LK Group, as COO, Boris held the role of Consumer Director at one of Australia’s leading telecommunications groups, M2 Group. As Consumer Director, Boris was responsible for a business unit of more than a half billion dollars with interests in telecommunications, energy and financial services. Overseeing a team of a few thousand employees, he was responsible for the business’ strategic development, overseeing the sales, marketing and operational functions of the business – delivering unprecedented numbers in subscriber growth. Boris is a Partner in PE firm, Queens Lane Capital, and holds a Bachelor of Laws and a Bachelor of Commerce specializing in accounting and finance. He has a strong background in leading product innovation and delivering on financial performance.

Julia Sartini

Chief Executive Officer

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Julia has held a number of senior and executive positions at global organizations spanning telecommunications to online wagering and gaming – including GM of Consumer Marketing of the M2 Group (ASX: MTU) in Australia, as well as Chief Operating Officer at International All Sports where she was instrumental in its sale to Paddy Power Plc’s Australian subsidiary, in 2009. A veteran of the online gaming industry, Julia headed up Retention Marketing for the Poker division at Osiris Trading (operators of the Fortune Lounge Online Gaming Group). Previously, Julia held positions as Account Director at Espial (one of South Africa’s foremost strategic design and implementation consultancies) and led the marketing strategy for Packard Bell NEC computers in South Africa. Julia holds an Honors degree in Information Technology from the University of Pretoria, South Africa.

John Harper

Co-Founder & Chief Technology Officer

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John is a 30+ year veteran of computer and telecommunications networking. Prior to Saisei, John led engineering at Anagran, overseeing the creation of their advanced flow-based traffic managers. He previously served at Cisco as the VP of IOS Routing, where he directed the strategy and development of routing protocols, multicast and IPv6 among other areas. John has also served in various senior development roles at Q3 Consulting and Digital Equipment. John is the author of more than 20 patents and holds a B.A. in Computer Studies from the University of Lancaster, England.

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