[3] In 1999, with Ireland-based real estate entrepreneur Brian Moran, he created his first company, a construction collaboration technology business called BuildOnline, where he also served as chief executive officer.

[9] At Upfront, Suster led investments in companies including Ring, Bird, Invoca, ThreadUp, MakeSpace, mitu, Nanit,[10] Osmo, Tact, and uBeam.

[11] Suster also led the initial funding round for, and was on the board of, Maker Studios, an online video talent agency (acquired by Disney in 2014).

[13] Unlike other Silicon Valley technology entrepreneurs, Suster has been open about turning down investments in potential start-up businesses that later became successful, including Uber.

[15] Less than a month later (11 March 2023), Suster called for calm as investors became concerned about the collapse of Silicon Valley Bank, suggesting a "handful" of VCs were creating panic.