An Introduction to Web Components and Polymer (Tutorial)

Modern web applications are not only complex to design but also quite difficult to develop. Given the range of tools involved, amount of testing required, and the combination of libraries/frameworks used, the development process has become harder. As the application scales over a period of time, it becomes harder to maintain the code and make enhancements.

For instance, take a look at the frontend code of these few popular websites:

via An Introduction to Web Components and Polymer (Tutorial).