Full-Stack Engineer. Merchant Portal & Checkout Layer

You will own two of the most consequential layers of the Aye platform: the merchant portal that surfaces real-time payments, loyalty, and CRM intelligence to retailers across APAC; and the checkout layer that routes and reconciles complex, multi-vertical transaction logic: abstracting regulatory, currency, and scheme complexity into a seamless experience for merchants and consumers. You’re self-driven, take end-to-end ownership, and thrive in a team that ships fast and iterates constantly., * Build and evolve the merchant portal: real-time analytics dashboards, loyalty programme configuration, multi-location CRM views, and role-based access control across merchant hierarchies

• Own the checkout layer: design and implement the transaction routing engine that handles multi-scheme payments (QR, card, biometric), multi-currency reconciliation, tax logic, and vertical-specific checkout flows (F&B, fuel, transit, retail)
• Design RESTful and event-driven APIs (Kafka, Pub/Sub) for merchant integrations, webhook delivery, and real-time event streaming
• Build multi-tenant, multi-region data architecture that enforces merchant data isolation while supporting cross-market reporting
• Instrument end-to-end observability: distributed tracing (OpenTelemetry), structured logging, latency SLA monitoring, and real-time alerting via PagerDuty or equivalent
• Contribute to continuous UX improvement: identify friction in merchant workflows through usage analytics, propose and ship improvements iteratively

• 4+ years full-stack experience with React (TypeScript) and Node.js (Express or Fastify); strong SQL and PostgreSQL skills
• Experience building multi-tenant SaaS platforms with complex role-based permission models
• Comfort designing and evolving high-concurrency transaction systems; understanding of idempotency, distributed locking, and eventual consistency
• Familiarity with event streaming (Kafka or Pub/Sub) and asynchronous processing patterns
• Cloud-native experience on GCP or AWS; understanding of container orchestration (Kubernetes, Cloud Run) and CI/CD pipelines
• Strong ownership ethos: you don’t wait to be told what’s broken, you find it and fix it
• Bonus: experience in payments (ISO 8583, EMV, QR code standards), loyalty platforms, or POS integrations