- Node.js/TypeScript : Experience with asynchronous programming, modular code design, and performance optimization.

- Express.js : Experience with Express.js or comparable web frameworks for building RESTful APIs, handling routing, middleware, and request/response lifecycles.

- Dependency Injection / Modular Architecture : Experience with Inversify or similar patterns/libraries (e.g., NestJS, IoC containers, or other DI frameworks).

- Pipeline / Workflow-Based Design : Understanding of modular, step-based processing architectures (e.g., middleware pipelines, command patterns, or job queues).

- API Design & Architecture : Strong understanding of REST principles, with experience designing and maintaining well-structured, scalable APIs.

- Integration & API Testing : Familiarity with tools like Nock.js, Supertest, Postman, or similar for mocking external APIs and validating end-to-end functionality in a test environment.