Lessons From Building a Global Platform for Seamless Payments

A few years ago, I led a product team at a global payments wallet company, where we launched a first-of-its-kind platform that streamlined card and account onboarding for consumers while benefiting banks and the wallet. At the time, our wallet had hundreds of millions of users worldwide, processing hundreds of billions in e-commerce payment volume. Yet despite the scale, one part of the user journey was painfully manual: adding payment cards and bank accounts. Users had to type long card numbers and banking details, often hitting roadblocks due to risk flags that required additional verification. Every friction point meant lost revenue for the wallet and for partner banks. As we evaluated the problem, we envisioned a novel way to solve this for users. What if users could authenticate once and have their payment instruments appear, activated and ready to use, without manual entry? The insights we collected during the concept stage became the foundation for our global bank partner platform. It powers card onboarding, user enrollment and payment credential provisioning across several banks globally, creating a new integration pattern where consumers no longer juggle card numbers, and both banks and FinTechs operate on shared identity-driven infrastructure. Beyond cards, it enabled additional features like linking rewards accounts, reducing friction across the financial ecosystem. The Core Problem Our data and research showed that consumers dropped off when prompted to enter payment details or when risk systems blocked transactions even after authentication. The pain points were threefold: Adding payment credentials without manual entry. Account opening for new users without redundant sign-up loops. Establishing a verified identity context both parties could trust. Solving this required rethinking onboarding not as isolated flows, but as a shared, secure identity orchestration across wallets and banks. Technically, that meant building a system flexible enough to integrate with diverse banking systems globally while maintaining a consistent and compliant user experience. Architecting for Fragmented Financial Systems Identity as the Anchor We anchored the platform around OAuth-based identity linking. Users could authenticate via login credentials or biometrics, and the resulting trusted session orchestrated microservices for identity, accounts, risk checks, user profiles and account-linking logic. But banks differ widely in their identity management, API conventions and sequence requirements. Our early pilot integrations were bespoke and required frequent alignment calls. To scale, we created a standard API specification that abstracted bank-side variance, defined mandatory and optional parameters, and implemented a microservice orchestration model resilient to sequencing discrepancies. Orchestrating Multiple Entry Points A key challenge was supporting users starting from either the bank app or the wallet app. Starting in the bank app, the bank redirected the user to the wallet interface with a session ID, sending backend payloads we cached until the user authenticated, consented to share data and selected accounts. We used the session ID to tie the context together, implementing short-lived cache entries, session reconciliation logic and fallback mechanisms for partial flows. Starting in the wallet app, users were deep-linked into their bank app. After authentication and account selection, the bank returned a unique session ID used in back-channel API calls to deliver credentials. Behind the scenes, a distributed state machine coordinated two apps, two backend systems and strict regulatory constraints to maintain integrity and session continuity. New users could be created in real time. If a user wasn’t recognized on redirect, the receiving party generated a verified profile automatically, removing redundant data entry and enabling fully provisioned accounts in under a minute. Navigating Ecosystem Constraints Even with the technical architecture solved, real-world constraints posed challenges: Long bank contracting cycles slowed onboarding; risk systems occasionally blocked legitimate users; customer service tools weren’t yet updated to handle the new flows and delayed biometric rollouts forced temporary webview-based flows. Additionally, banks’ card and checking/savings systems operated in silos, requiring carefully orchestrated integration. Early Failures That Taught Us the Most The platform’s toughest lessons emerged at the seams between systems. Early on, some banks launched before fully updating their risk models. Authenticated users triggered high-risk flags because their systems had never seen card provisioning without manual entry. Sessions looked clean on our side, but transactions were blocked. We addressed this by co-developing risk-mapping guides, shared event schemas and monitoring hooks so banks could interpret these flows reliably. Customer service was another critical failure point. Support teams lacked context or tools to troubleshoot multi-app flows. Users hit edge cases, banks saw spikes in calls, and our logs showed nothing broken. Resolving this required journey visibility for support teams, human-readable error interpretations and CRM templates, effectively treating support as part of the system runtime. Analytics visibility was similarly challenging, wherein drop-offs during login or account selection were opaque without instrumentation in the banks’ apps. We implemented a shared event schema and lightweight SDKs, enabling end-to-end journey reconstruction across institutions. In terms of pure engineering issues, race conditions between microservices and apps occasionally caused identity or payload data to arrive out of sequence. We adopted state-machine-driven orchestration, asynchronous callbacks, stricter idempotency rules and distributed tracing, ensuring robust flows under load. In the first wave of launches, some banks couldn’t support biometric authentication, forcing us to rely on webviews. While functional, the flow felt clunky, reducing login success rates and increasing friction. However, for the partners that launched with biometrics, we were able to collect favorable data and use it to accelerate mobile updates and improve adoption across multiple banks. The Impact Once live, the platform transformed onboarding. Card provisioning became nearly invisible, drop-offs fell sharply and successful completions increased. Users engaged with additional features such as linking rewards accounts and exploring “pay with rewards,” boosting transaction volumes and retention. For the wallet, fewer abandoned flows meant higher customer lifetime value and the ability to roll out new features without redesigning the user journey. For users, the experience became intuitive and secure: Authenticate once, and your payment instruments are ready to use. The platform validated that cross-institution workflows can be both frictionless and secure, creating a repeatable model for future bank integrations globally. Lessons Learned Establishing identity as the backbone of cross-institution experiences serves well in building collaborative experiences for a win-win. Standardization with flexible edges allowed us to scale globally: A rigid core for identity and session handling ensured reliability, while adaptable layers accommodated diverse bank implementations. Supporting all entry points from day one maintained UX consistency and operational observability. Operational readiness mattered as much as technical design. Risk models, support workflows and analytics frameworks needed to evolve alongside the platform. Product leadership required balancing technical rigor with strategic foresight: building observability, fallbacks and reconciliation mechanisms while guiding partner teams toward a shared vision. Ultimately, resilient systems depend as much on orchestrating the ecosystem as on writing code. Conclusion Delivering a globally scalable bank-partner platform requires more than engineering skill; it demands collaboration across organizations, systems, and experiences. By centering identity and designing for resilience and flexibility, we turned a historically painful onboarding process into a seamless, high-impact experience. This platform demonstrates how FinTechs and banks can work together to deliver real-world value at scale, setting a blueprint for future identity-driven integrations across the financial ecosystem. The post Lessons From Building a Global Platform for Seamless Payments appeared first on The New Stack.