[2] After graduating from college, Koyfman joined Bear Stearns as an investment banker, where he worked on mergers and acquisitions and raising financing for media, technology and entertainment companies.
[4] Among the first investments led by Koyfman at Spark were stakes in online marketplaces Skillshare and WorkMarket.
[2] Later investments include eyeglass retailer Warby Parker,[2] fraud prevention software company Sift Science,[5] financial service provider Plaid (company), Kitchensurfing, Aviary, DIY, FundersClub, Consumer United, gdgt, and Svpply.
[6] He became a member of the Board of directors for Skillshare, WorkMarket, Aviary, Plaid, DIY and Consumers United.
[16] In 2013, Koyfman became an early backer and member of the board of directors of Sefaria, a non-profit online open source free content library of Hebrew and English Jewish texts.