Sony & telecom payment systems
Payment APIs and resilient partner integrations
Developed Java/Spring transaction flows for cloud payments and direct carrier billing with idempotency, retries and reconciliation.
The system
Across product and telecom projects, I worked on payment capabilities integrating external gateways and carrier systems with Java/Spring services, AWS components and relational persistence.
What had to be solved
Payment systems must handle retries, delayed partner responses and partial failures without creating duplicate charges or losing the ability to reconcile a transaction later.
Non-negotiable requirements
- External partners exposed different contracts and failure behavior.
- Repeated requests had to remain safe for charge and refund operations.
- Failures needed operational recovery paths rather than manual database correction.
- Payment data and status transitions required clear auditability.
What I implemented
- Built Spring Boot REST APIs and partner-specific request/response mappings.
- Integrated card and UPI payment flows for a Sony cloud product using gateway SDKs and AWS Lambda.
- Implemented idempotent transaction handling, reconciliation jobs and exception workflows.
- Applied timeouts, retries, circuit breakers, bulkheads and dead-letter processing to carrier integrations.
- Expanded automated regression coverage for transaction and failure scenarios.
Key implementation choices
Design for duplicate delivery
Transaction identity and idempotent handling ensured that retried requests did not create duplicate financial operations.
Isolate partner failure
Timeouts, circuit breakers and bulkheads prevented one unstable integration from consuming the entire service.
Reconcile asynchronously
Scheduled and exception workflows recovered uncertain transactions when synchronous confirmation was unavailable.
Engineering outcome
- Payment capabilities supported multiple modes and external partner systems.
- Retries and uncertain responses could be handled without compromising transaction integrity.
- Reusable adapter patterns reduced the effort required to add or change partner integrations.