Hiring a Koa.js developer brings numerous benefits. They can create efficient and robust web applications and APIs using Koa.js, a next-generation framework for Node.js. Koa.js provides a lightweight, expressive, and robust foundation for web applications and APIs. It allows developers to ditch callbacks and greatly increase error handling capabilities, which results in less cluttered and more readable code. A Koa.js developer can leverage these features to create highly performant and scalable applications, ultimately enhancing user experience and driving business growth.