Smith was previously technology consultant director at MEC. Prior to that he worked at GroupM as a digital operations specialist.
He will work with the head of product for AOD (Audience on Demand), Paul Silver who has been responsible for "implementing and refining the AOD product roadmap for the UK," according to VivaKi.
Marco Bertozzi, managing director of VivaKi Nerve Centre Europe, Middle East and Africa, said: "This year has seen huge growth for us, not only in display but also through expanding AOD into other channels and we have big ambitions for next year.
"Geoff brings proven experience in this space and working together with the talented people within each of the agencies ensures we are well placed to achieve them."
Smith said: "With the continued development in the exchange driven market, there could not be a more exciting time to join, pushing the performance envelope on behalf of clients whilst helping VivaKi to continue driving innovation across the industry."