API Integration & Web Application Developer
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API Integration & Web Application Developer
From ACH to Card Payments: Building Scalable Payment Systems for US Businesses
Over the past few years, I’ve worked closely with US-based businesses to design and implement secure, scalable payment systems across ACH, online card payments, and card-present (terminal) environments.
My experience spans platforms like North.com (http://North.com), NMI, and other payment APIs—supporting everything from recurring ACH billing to fully integrated in-person payment solutions using physical terminals.
On the ACH side, I’ve handled bank account verification, transaction lifecycles, and returns such as NSF and failed debits. ACH systems require careful management of delayed settlements, webhook events, and reconciliation—especially within US financial workflows.
For online card payments, I’ve implemented secure gateways, tokenization, and optimized checkout experiences to ensure fast, seamless, and PCI-compliant transactions.
I’ve also built and deployed card-present solutions, including:
– EMV terminal integrations
– Tap, dip, and swipe transaction flows
– Device configuration and deployment
– Real-time syncing with backend systems
– Handling reversals, refunds, and partial approvals
A critical part of every integration is compliance and security. My work ensures:
– PCI DSS compliance for card data protection
– Tokenization (no sensitive data storage)
– Secure API authentication and encryption
– Reliable webhook handling and audit-ready transaction logs
From a technical perspective, I specialize in building robust API integrations, webhook listeners, retry mechanisms, and fail-safe systems that continue to operate reliably under real-world conditions.
Key solutions I’ve delivered:
– ACH debit and recurring billing systems
– Online card payment integrations with secure token flows
– Card-present terminal integrations
– Real-time transaction systems using webhooks
– Payment failure handling and reconciliation logic
– CRM and internal dashboard integrations
Working in the US payments ecosystem has given me deep exposure to compliance requirements, operational challenges, and the importance of building systems that are both secure and scalable.
My focus is simple: build payment systems that are reliable, compliant, and seamless—whether online or in-person.
Open to collaborations in fintech, payments, and API integrations.
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