Payment Systems Engineering
Payment switches, gateways, and settlement flows engineered for accuracy, reconciliation, and uptime — built to handle transaction volume without breaking.
- High-availability
- PCI-aware
- Multi-rail
Systems that move money correctly, every time.
We build the payment switches, gateways, and settlement pipelines that sit between banks, processors, and merchants — matching, reconciling, and settling transactions at scale. Every flow is engineered with monitoring, retries, and audit trails, so failures are caught, not hidden.
Built to fail safely, reconcile automatically, and account for every transaction.
What We Deliver
Six areas of work that make up most payment systems engagements.
Payment Switch Integration
Routing logic that connects your systems to card networks, UPI rails, and bank switches.
Payment Gateway Development
Checkout and merchant gateway flows built for high-volume transaction traffic.
Settlement & Reconciliation
Automated settlement and reconciliation across banks, processors, and merchants.
Fraud & Risk Controls
Real-time transaction screening and risk rules embedded in the payment flow.
Multi-Rail Support
Support for cards, UPI, net banking, wallets, and emerging payment rails.
Monitoring & Uptime Engineering
Observability and failover built in to keep payment flows running.
Our Process
A five-stage engagement, from volume assessment to production operation.
Assess
Review existing payment flows, volumes, and integration points.
Architect
Design switch, gateway, and settlement architecture for your transaction volumes.
Build
Engineer and test payment flows against real-world failure scenarios.
Certify
Complete network and regulatory certification before go-live.
Operate
Monitor uptime, reconciliation, and settlement in production.
Fintech Application Development
Customer and back-office applications for regulated products.
API Development
Documented, versioned APIs for partners and products.
Microservices Architecture
Domain-driven services that scale independently.
Legacy Modernisation
Phased modernisation of core and legacy platforms.
Let's engineer your next payment system.
Tell us what you're building or modernising — a member of the Unlock team will get back to you.