Challenger banks, incumbent banks, and all of the many businesses that are making inroads into any kind of banking service all have something in common: when it comes to launching a new product like a credit line or a deposit or current account, these days many of them are opting not to build from the ground up, but are instead using third-party technology to power these services. Today, one of the big players in providing that tech is announcing a large round of funding to expand its business, underscoring the…