Ask HN: Recommended FDIC-insured bank that supplies services to fintech apps?

I am interested in building a fintech app that would need to open savings accounts on behalf of users. I don’t have any ability to negotiate such an arrangement directly with a bank. My hope is to find a bank that caters to fintech apps with API-enabled banking services that are FDIC-insured. Think FDIC-as-a-service in the same way that Plaid offers connectivity-as-a-service.