As a lawyer, Simon worked in commercial and corporate law, specialising in venture capital investment. He has since worked in venture capital as an investment partner and has served as a senior executive for several US technology companies, including as the former Chief Executive Officer of DreamHost, the former Co-Founder of Inktank Storage Inc. and former Director and Founding Member of the OpenStack Foundation.

• Managing Director of Ocean Avenue Ventures - a consulting and advisory firm for internet, digital media and web analytics companies.
• Advisory Board Member of Aptira (OpenStack Services in the Asia-Pacific and Europe) and Duda (a mobile website platform).
• Technical Advisory Committee, Museum of Science Fiction. The Museum aims to be the world's first comprehensive science fiction museum.
• Recognised as the 2016 ANU Alumnus of the Year (Innovation & Entrepreneurship).