Why Retool’s CEO Took A ‘Risky’ Fundraising Approach On The Way To A $1.9 Billion Valuation Retool CEO David Hsu took an unusual approach to his low code software startup's Series C funding round, raising just $20 million from fellow founders like Stripe's John and Patrick Collison and former GitHub CEO Nat Friedman in a bid to limit dilution for Retool employees.