This is a reference build: what we design and construct when a payments company needs a consumer wallet. The requirements repeat across markets — peer-to-peer transfers, QR merchant payments, bill pay, and mobile top-ups, all in an app that has to feel instant to people using digital payments for the first time. The engineering weight sits under the surface: a ledger that balances, idempotent transaction handling, KYC and onboarding flows, fraud rules that catch abuse without blocking genuine users, and a payments architecture aligned to PCI DSS from the first sprint rather than retrofitted before an audit.
The inherited app stored card data insecurely and had no separation between the ledger and the presentation layer, making PCI DSS certification impossible. Every new feature risked breaking settlement logic.
We rebuilt the platform as event-sourced microservices with a double-entry ledger at the core and tokenized card storage via a certified vault. The new architecture passed PCI DSS Level 1 assessment on the first audit.
Promo abuse rings and SIM-swap account takeovers were draining the client's incentive budget. Manual review queues took 48 hours, by which time funds had already moved through mule accounts.
A streaming risk engine scores every transaction in under 80 milliseconds using device fingerprinting, velocity rules, and a gradient-boosted model retrained weekly. High-risk events trigger step-up biometric verification instead of blanket blocks, protecting conversion.
Bank Indonesia, the BSP in the Philippines, and the State Bank of Vietnam each impose different KYC tiers, transaction limits, and reporting formats. Hard-coding one country's rules would have blocked expansion into the others.
KYC tiers, limits, and regulatory reports are defined as per-country configuration rather than code. Launching in Vietnam required policy entries and local language packs — not a new codebase — cutting market entry time from months to weeks.
This is a reference build: the scope, architecture, and engineering decisions we work through when a clinic group asks for a patient platfor…
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This is a reference build: the fleet platform we put together when dispatch is still running on spreadsheets, phone calls, and three separat…
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This is a reference build: what a D2C brand needs when it is selling through marketplaces, a basic storefront, social channels, and physical…
Read case studySend us the part you are stuck on. Scoped work is quoted from $12, and a full platform gets a custom quote after a discovery call.
