An Annyang.js developer specializes in using the Annyang.js library, which is a JavaScript-based tool for adding voice recognition capabilities to websites. They can create interactive experiences, such as voice-activated commands or dictation, enhancing accessibility and user engagement. Their responsibilities include designing, coding, testing, and debugging these features, ensuring they work seamlessly across different browsers and devices. They also need to maintain and update the speech recognition features as needed. Additionally, they must collaborate with other developers and stakeholders to integrate these features into the overall website design and functionality, while also considering user experience and privacy issues.