Railsbank, the London-headquartered Banking-as-a-Service platform, has raised $37 million in new growth funding. Leading the round is MiddleGame Ventures and Ventura Capital, which are both existing investors in Railsbank. Also participating is Anthos Capital, Global Brain, Clocktower Technology Ventures, Moneta VC, Mitsui Fudosan and Firestartr. Nigel Verdon, co-founder and CEO of Railsbank, tells me the injection of capital will be used to continue expanding the fintech’s global footprint and for further product development. This will include the launch of “credit cards as a service” in the U.S. and expand its…