Here are some of the gems for full stack developer..

Stack Overflow: A great community for asking and answering technical questions related to programming.

GitHub: A platform for sharing and collaborating on open source projects, with a large repository of full stack projects.

Codecademy: An online platform for learning how to code, including full stack development.

Udemy: An online learning platform that offers a wide range of courses on full stack development.

FreeCodeCamp: A non-profit platform that provides a full stack development curriculum, along with opportunities to build projects and earn certifications.

W3Schools: A website that provides tutorials and references on web development technologies, including full stack development.

HackerRank: A platform that provides coding challenges and competitions, including full stack development.

Coursera: An online platform that offers courses from top universities and institutions, including courses on full stack development.

Udacity: An online platform that offers nanodegrees in full stack development, as well as courses on specific technologies.

These websites provide a wealth of resources and opportunities for full stack developers to learn, practice and improve their skills.