API Integration in AI powered web app

Description: About the Project We are building an AI-powered web application designed to streamline automated workflows and dynamic user interactions. The core front-end and back-end architectures are already established, but we need an experienced full-stack developer to connect key external APIs, implement robust backend routes, and ensure smooth data flow between our interface and our AI services. What You Will Do Integrate third-party APIs and custom AI model endpoints into our existing web application stack. Build, optimize, and secure RESTful endpoints to handle asynchronous requests and large data payloads cleanly. Implement effective error handling, retry logic, and rate-limiting to maintain high performance under peak usage. Work closely with the front-end team to ensure payload structures align seamlessly with state management. Write clean, self-documenting code and provide brief technical notes for the endpoints created. Key Requirements Proven track record of integrating complex APIs, webhooks, and asynchronous services in modern web frameworks. Solid experience working with AI model provider APIs (such as OpenRouter, OpenAI, or custom model deployments). Hands-on proficiency with modern JavaScript/TypeScript backend setups and client-side integration patterns. Strong understanding of secure authentication methods, environment management, and data validation practices. Ability to troubleshoot network bottlenecks, payload mismatches, and unexpected API timeouts quickly.