Engineering a High-Throughput B2B Payment Switch with Zero Balance Drift
How WaapCoders replaced a legacy PHP core with an event-driven Node.js, Redis and PostgreSQL payment switch for Magic Pay Solution.
The client
- Client
- Magic Pay Solution
- Industry
- Fintech & Banking Infrastructure
- What we built
- B2B payment switch (fintech infrastructure)
The challenge
A fast-scaling financial technology provider faced database locking issues and timeout bottlenecks during peak evening settlement runs on their legacy PHP core.
The solution
Engineered an event-driven transaction switch in Node.js and Redis. Implemented pessimistic row-level database locking in PostgreSQL, multi-bank failover routing, and signed HMAC webhook notifications.
How we implemented it
Event-driven transaction switch
Payment requests run through an event-driven switch built in Node.js and Redis, replacing the legacy PHP core.
Row-level locking in PostgreSQL
Pessimistic row-level locks keep balances consistent while many transactions run at the same time.
Multi-bank failover routing
Transactions are routed across banks, with failover when a route is unavailable.
Signed webhook notifications
Status callbacks are sent with HMAC signatures so the receiving system can verify them.
Secure, containerised delivery
The platform is packaged with Docker and uses HSM-backed encryption for sensitive operations.
The results
“WaapCoders engineered our entire B2B fintech core from the database up. Their understanding of bank settlement and webhook reliability is exceptional.”