An Aurelia.js developer designs and implements web applications using the Aurelia.js framework. They engage in coding, debugging, and testing to ensure smooth and efficient operation of applications. They utilize Aurelia.js' capabilities to create scalable and maintainable code, leveraging its focus on web standards, extensibility, and advanced JavaScript language features. They also integrate APIs, design user interfaces, and optimize application performance. Additionally, they collaborate with other team members to define functionalities, code reviews, and problem-solving. They are expected to keep abreast of the latest developments in JavaScript and the Aurelia.js framework to continually improve their applications.