Iyyappan User

I’m a Senior Full Stack Engineer with 7+ years of experience delivering production-grade web and mobile applications for fintech, community, and real-time platforms. I focus on building secure, scalable systems end-to-end—from architecture to code, deployment, and production support.

In my current role with a Canadian tech company (remote via global payroll), I architect React Native and Next.js/React.js solutions for thousands of concurrent users. I designed and optimized GraphQL/REST APIs, reducing average response latency by 35% using query batching and caching, and I improved PostgreSQL performance by cutting slow-query count by 50% through indexing, query-plan analysis, and schema normalization.

I also own infrastructure and delivery quality, managing AWS (EC2, S3, RDS) with CI/CD pipelines using GitHub Actions to achieve zero-downtime deployments. I lead technical architecture reviews, mentor junior engineers, and implement real-time capabilities (WebSockets, push notifications) plus offline-first synchronization for mobile experiences.

Earlier, I shipped cross-platform React Native products for iOS and Android and built backend services with Node.js, Express.js, and PostgreSQL supporting 10K+ daily active users. I’ve integrated Stripe/Razorpay payment gateways with role-based access control and audit trails, and I bring a performance-first mindset rooted in system design, testing, and maintainable code.