Payment APIs
Payment APIs are where partner enablement, idempotency and developer experience meet regulation. Essays here cover API surface design, local payment methods and the developer experience underneath.
Field notes for this hub.
UK Open Banking Has a Product Scale Scorecard Now
UK Open Banking's one billion payments and 100 billion API calls should push product teams from adoption storytelling into a harder scale scorecard: reliability, consent completion, VRP quality, fraud, disputes, and cash-flow outcomes.
Capital One's Discover Test Turns Issuing Into Network Strategy
The Discover integration is not just a card-portfolio migration. It is a test of whether an issuer can move economics, acceptance, wallets, servicing, and customer trust onto a new network without making the customer feel the operating model.
Stripe Projects Shows Agentic Products Need Cost Boundaries
The product lesson is not that agents can provision services. It is that agent-native products need explicit cost, credential, environment, and evidence boundaries.
Mercado Pago's Claude Plugin Turns Payment Docs Into Controls
Faster scaffolding is easy; faster confidence is the real product. Mercado Pago's four Claude Code workflows move payment rules, webhook tests, credential checks, and review into the developer's path, as long as version drift is governed.
Mollie's EEA Expansion Is a Localisation Infrastructure Bet
Mollie is committing EUR350 million over five years to ship local payment methods, onboarding, support, settlement, and reconciliation as one merchant operating system. Country coverage was always the weak proxy.
Boku's UPI Launch Is a Local-Rail Export Story
Boku's first cross-border UPI transactions are not just another local payment method. They show how domestic instant rails are becoming export infrastructure for global checkout.
Scheme Settlement: T+1 vs T+0 vs Real-Time and the Working-Capital Math That Decides
Every PM in card acquiring eventually meets the merchant who wants 'same-day settlement'. The mechanics behind the ask are usually misunderstood by both sides. Scheme settlement timing is partly a product feature, partly a working-capital problem, and almost entirely about which balance sheet carries the float.
RAG for Merchant Integration Support: A Production Playbook
RAG is the right starting architecture for merchant integration support, but only if the corpus is curated, the citations are mandatory and the fallback paths are designed before launch.
PMBOK + Agile Hybrid Frameworks for Payments Teams
A regulator wants a stage-gated evidence trail; a product team wants two-week cycles. At Simpaisa I ran 12 squads by classifying each workstream as Agile or Capital and applying the framework that fits. This is that operating model.