A stealth startup based out of the USA, has an MVP in progress to unify banking, bill payments, recharge, rewards, and embedded commerce into one secure, scalable mobile app without cross-domain coupling.

Architecture Summary

• Distributed microservices: banking, billers, rewards, e-commerce, KYC, identity, notifications.

• Isolated domains: failures in rewards/e-com never impact banking.

• Gateway + Router pattern: token validation, rate limits, request routing, API quotas.

• Kafka-based async mesh for high-volume events (bill payments, rewards issuance, e-com actions).

• Layered design: Core framework → DB layer → services → app framework → mobile/web clients.

Key Capabilities

Banking

• Open Banking integration via secure Banking Service.

• Split transactional vs non-transactional APIs.

• Tiered auth: mPIN → OTP → biometrics for high-value transfers.

Bill Payments / Utilities

• Dynamic biller onboarding (no core code change).

• Biller Router for external API integration.

• Independent scaling during peak utility cycles.

Rewards & Coupons

• Campaign engine, partner onboarding, rule-driven coupon awarding.

• Runs independently of banking and billers.

Embedded E-Commerce

• Router loads partner portals inside the app.

• Payments confirmed via banking mPIN for unified checkout.

Security Model

• Multi-factor identity (device binding, OTP, password, biometrics).

• Gateway-level token verification + service-level authentication.

• Role-scoped access for all third-party integrations.

Data Architecture

• SQL for transactional records.

• NoSQL / Mongo for content + configuration.

• Graph DB for event tracking + recommendation signals.

• Dedicated DBs per domain: banking, billers, rewards, e-com, users, events.

Performance & Scaling

• Async operations via Kafka.

• Atomic CRUD + batch APIs.

• Horizontal scale for banking and e-commerce services.

• Full request tracing across services.