A JWS (JSON Web Signature) developer is responsible for creating, testing, and implementing digital signatures in JSON-based web applications. They work with cryptographic algorithms like RSA and HMAC to ensure data integrity and authenticity in client-server communication. They encode and decode JWS tokens, handle exceptions, and troubleshoot any issues related to digital signatures. They also work closely with other developers to integrate JWS into larger software systems, ensuring secure, efficient, and seamless data exchange. Additionally, they often document their work, providing clear instructions for other team members.