A Fullstack Developer is responsible for designing, developing, and maintaining end-to-end web applications. They work on both front-end and back-end aspects of the application and have knowledge of various technologies, such as HTML, CSS, JavaScript, React, Node.js, Express, and databases like MongoDB or MySQL. They are able to create visually appealing and user-friendly websites and ensure their functionality by testing and debugging code. Fullstack Developers collaborate with teams, including designers, software engineers, and product managers, to create and implement innovative solutions. Additionally, they stay updated with the latest web development technologies and industry trends to continuously improve their skills.