Sadad-Sabb
SADAD Bill Payment & MOI Integration
Payment and government system integration. High-integrity bill payment flows with policy and limit enforcement.
Impact — Zero payment discrepancies in production; 100% policy and limit enforcement; sub-second response for eligibility checks.
Problem
Bill payment and MOI integrations required transactional integrity, idempotent retries, and hard policy/limit enforcement with zero balance drift.
Approach
NestJS + TypeORM on Oracle with gRPC/HTTP integrations, idempotent payment flows, policy engines, schedulers for reconciliation, and structured audit logging.
What shipped
- NestJS services with TypeORM and Oracle DB; transactional integrity for all payment and refund flows
- gRPC and Axios integrations with MOI/SADAD; reduced integration errors via retries and idempotency
- Policy and limits enforcement services; prevented over-payment and duplicate submissions
- Transaction lifecycle management and scheduler; improved reconciliation time by ~50%
- Structured logging and notification flows; faster dispute resolution and audit compliance
Stack
Related writing
- Designing Idempotent APIs for Payments
How idempotency keys, deduplication, and clear status models prevent double charges and support safe retries.
- Backward-Compatible API Versioning in Production
How to evolve REST and gRPC APIs without breaking mobile clients and partner integrations.