NMI

NMI provides an embedded payment solutions platform, offering a white-label payment gateway that enables businesses to accept payments across e-commerce, in-person, and mobile channels. It focuses on providing flexible integration options for developers and robust tools for merchant management, fraud prevention, and reporting.

NMI is a strong match for the Stripe Payments Platform concept. It offers a comprehensive payment gateway solution that includes core payment processing for various channels (e-commerce, in-person, mobile), robust developer APIs and SDKs for integration, and features like fraud defense and reporting. While it doesn't explicitly mention subscription management in the same way Stripe Billing does, it does offer recurring billing and customer vault features which are related. It also provides several 'other' features like in-person payment solutions (Stripe Terminal equivalent), invoicing, multi-currency support, global payment methods, webhooks, and a customer portal.