In the late nineties, Warner started his career working at CBRE, where he proved himself to be a top rookie producer. During his tenure at CBRE, he was selected as a member of the CBRE Life Sciences advisory group. This experience provided him with a strong innovation property experience, which would stay with him throughout his career. Following up on his success at CBRE, Warner joined the development company, Phase 3 Properties, now Phase 3 Realty Partners. As a principal of Phase 3, Warner was exposed to complex developments and consulting assignments on behalf of major corporations, universities, and municipalities throughout the United States. In 2013, Warner founded IPG in San Francisco.