Balady Billing System
2024
Canonical microservices ensemble for NHC-integrated payment processing, points conversion, and wallet management. 13 services with saga-style compensation, dual-verification on every callback, and circuit breakers on every external dependency.
The problem
Citizens use the Balady super-app for hundreds of transactional services — licences, certificates, infringements, fee payments. Every transaction has to hit NHC’s payment gateway, reflect on the citizen’s wallet, settle points (rewards), and reconcile back to the licence-issuing service. Failures anywhere in that chain are visible to the citizen and audited by the bank.
The architecture
A 13-service ensemble across three surfaces — payment-processing, wallet, and domain-integration. Apigee fronts all ingress with rate-limiting and OAuth scoping. Saga-style compensation rolls back partial transactions when any leg fails. Dual-verification on every NHC callback ensures no settlement event is applied twice. Circuit breakers isolate failures of any single external dependency.
Data tier
Oracle 19c for transactional state (audit trail mandated by regulators). Redis Cluster for hot read paths (eligibility, wallet balance). Apache Kafka carries asynchronous settlement events to the BI tier and downstream consumers (Debts Hub, Commercial Domain).
Outcome
The canonical payments substrate for the Balady ecosystem. All consuming services (licences, certificates, certified observer) integrate via the same RabbitMQ/Kafka events, so changes propagate uniformly.