Usama Bin Sadiq

Architected modular RESTful/GraphQL APIs with NestJS and Node.js using dependency injection and a clear separation of Controllers, Services, and middleware with centralized error handling. Integrated Kafka/RabbitMQ to support event-driven asynchronous communication in a microservices setup. Designed and optimized PostgreSQL schemas with indexes, joins, and transactions for multi-tenant workflows. Implemented JWT authentication and role-based access control (RBAC) using NestJS Guards and Pipes. Built AWS S3 pipelines for multipart uploads and presigned URLs for large file handling. Developed React frontend modules with hooks, context, and Redux for consistent state synchronization with backend APIs.

Developed NestJS APIs for blockchain smart contract interactions, including transaction handling, token burning mechanisms, and secure data flows. Integrated Stripe for subscription and one-time payments, managing payment sessions, webhooks, and data integrity. Built React components using hooks and Redux for stable state management and smooth UI updates. Designed service layers to fetch and normalize data from third-party APIs (e.g., CoinMarketCap and Molaris) for blockchain analytics. Secured blockchain and payment workflows with RBAC using NestJS Guards to ensure robust transaction processing.

Built RESTful APIs using Node.js and Express.js to support frontend features and data operations. Implemented request validation with Joi and JWT-based authentication to improve backend security. Debugged and resolved production issues by analyzing logs and reproducing errors in development. Collaborated with the frontend team to integrate APIs with React components and ensure correct data flow. Created modular and reusable backend services following coding standards and best practices.