SmartPay — Logistics Payments Platform
A high-throughput, Kubernetes-native logistics payments platform architected across seven Domain-Driven Design (DDD) bounded contexts. The system handles complex carrier settlements, factoring, proof of delivery verification, and payment reconciliation at scale.
Architecture & Bounded Contexts
The platform is split into seven strictly schema-isolated bounded contexts to prevent cross-domain database coupling:
- Double-Entry Ledger: Immutable accounting journal enforcing zero-sum financial transactions.
- Invoicing & ePOD: Automated invoice generation triggered by electronic proof of delivery.
- Idempotent Payments: Guaranteed once-and-only-once payment processing with deduplication keys.
- Factoring: Early invoice settlement and credit underwriting for carriers.
- Reconciliation: Continuous transaction status reconciliation against external banking feeds.
- Risk Assessment: Real-time fraud detection and limit enforcement.
- Notifications: Multi-channel alerting for payment status and delivery receipts.
Technical Highlights
- Isolation & Communication: Internal gRPC for ultra-low latency synchronous communication; Redpanda for high-throughput distributed event streaming.
- Transactional Outbox: Eliminates dual-write anomalies between relational database state commits and event publishing.
- Security Posture: Internal-only microservices deployed inside private cluster subnets; only the API gateway is publicly reachable.
- Deployment Hardening: Validated via automated, ephemeral KinD (Kubernetes in Docker) end-to-end CI pipelines in GitHub Actions.
Technology Stack
- Backend: Java 25 LTS, Spring Boot
- Data & Events: PostgreSQL (schema-per-context), Redpanda, Transactional Outbox
- RPC & Networking: gRPC, Protocol Buffers
- Infrastructure: Kubernetes, KinD, Docker, GitHub Actions CI/CD