Overview
Implemented and maintained payment gateway integrations across multiple web applications, supporting credit card payments, wallets, and 3D Secure flows. Focused on building reusable, secure modules that adhere to PCI compliance and support rapid scaling.
My Role
- Full Stack Developer & Backend Engineer
- Designed GraphQL APIs to handle payments, refunds, and webhook event processing
- Secured transaction flows and ensured graceful error handling across services
Key Highlights
- Developed a reusable GraphQL payment interface that abstracted provider-specific logic, simplifying integration across services.
- Implemented secure webhooks for handling real-time payment events including success, failure, refunds, and disputes.
- Enabled 3D Secure and tokenized card flows with fallback strategies for non-compliant cards.
- Built in retry, circuit breaker, and error-logging patterns to ensure resilience and observability.
- Supported multi-currency and country-specific payment rules, including tax handling and VAT calculation.
- Integrated real-time fraud detection hooks and IP-based validation layers for risk mitigation.
- Created automated test suites and sandbox simulators for payment provider flows (Stripe, Razorpay).
- Designed the system with extensibility in mind to allow future integrations with crypto wallets or bank aggregators.
Tech Stack
Node.js, NestJS, Apollo GraphQL, Stripe SDK, Razorpay, TypeORM, PostgreSQL, Adyen, TypeORM, PostgreSQL, JWT, Webhooks, Prometheus, Sentry
