A MERN stack developer specializes in creating web applications using four core technologies: MongoDB, Express.js, React, and Node.js. They leverage MongoDB for database management, Express.js for server-side application logic, React for building dynamic user interfaces, and Node.js for server-side scripting. MERN stack developers adeptly manage both front-end and back-end development, ensuring seamless communication between components. Their expertise enables them to design and implement scalable, real-time, and efficient web applications. MERN stack developers are highly sought after for their ability to create robust and modern web experiences.