He was the co-founder and CEO of Sidecar, a San Francisco, based an on-demand peer-to-peer taxi service that later pivoted away from ridesharing toward deliveries of various items.
In 1996, Paul co-founded and launched his first startup with Mark Pincus, Freeloader, Inc., a web-based push technology service.
[7] In 1998 Paul founded Brightmail (previously known as "Bright Light Technologies"), an e-mail filtering company, and raised $55 million in three rounds of venture capital led by Accel, TCV and Symantec.
In February 2012 Paul co-founded Sidecar, an on-demand peer-to-peer ridesharing service with Jahan Khanna, Adrian Fortino, and Nick Allen.
[2][16] Paul launched Spring Free EV in 2021, a fintech company designed to have climate level impact by accelerating adoption of electric vehicles.