• Developed Express.js microservice handling Stripe webhooks with idempotent processing to prevent duplicate orders, cryptographic signature verification, and structured Pino logging, implementing fault tolerant architecture where email failures don’t block order creation and Zod runtime
validation prevents malformed data.
• Designed graceful degradation patterns and atomic operations: batch Firestore stock updates,
request ID middleware for distributed tracing, and Stripe webhook error handling (return 200 to
prevent infinite retries while asynchronously sending email notifications to users), ensuring data
integrity across order creation, inventory management, and cart cleanup.
• Optimized webhook performance using Stripe expand parameter to fetch session, line items, and
products in single API call, with compression middleware for reduced response sizes and Helmet security headers for production protection.

• Developed full-stack e-commerce application using React, Next.js 15, TypeScript, and Tailwind-
CSS, following clean architecture and separation of concerns principles with reusable components
and server-driven architecture.
• Designed dual filtering strategies optimized for different user contexts: implemented server-side
filtering with IntersectionObserver-based infinite scroll for customers (reducing initial load and
supporting large catalogs), while utilizing client-side memoized filtering for admin interfaces (enabling instant filtering without network latency on limited datasets).
• Designed centralized state management with React Context and custom hooks, supporting optimistic updates, Firestore sync, and rollback on failure, reducing unnecessary re-renders across
20+ components.
• Built multi-layered security architecture featuring HttpOnly cookies with SameSite protection,
Firebase Admin token verification with revocation checks, Content Security Policy headers, CSRF
defense through Server Actions, and role-based authorization supporting multiple user roles (customer, admin, superAdmin).
• Leveraged Next.js 15 Server Components and Server Actions for server-side logic, achieving zero
REST API endpoints while maintaining type-safe client-server communication and improved performance through reduced client-side JavaScript.
• Integrated Stripe checkout with webhook-based order processing, automated email notifications,
and real-time inventory synchronization via Express.js microservice.
• Ensured code quality through unit testing of utilities and components, plus end-to-end Playwright
tests covering authentication flows and checkout journey.