A full stack web developer is a professional who possesses expertise in both front-end and back-end web development. They are proficient in a variety of programming languages, frameworks, and tools necessary to build and maintain dynamic web applications. Their responsibilities typically include designing user interfaces, implementing features, writing server-side logic, database management, and ensuring the application's performance, security, and scalability. Additionally, they often collaborate with designers, other developers, and stakeholders throughout the development process to deliver high-quality web solutions that meet client requirements.