A JR web developer is a professional who is starting his career in the area of creating websites and web applications. He is responsible for programming, testing and correcting the code that runs in the user's browser, using tools such as HTML, CSS, JavaScript, etc. He is also responsible for ensuring the quality, security and performance of the website or application.

A JR web developer can do various tasks, such as:

- Develop, test and maintain the code that defines the structure, style and interaction of the website or application;

- Create and apply visual elements, such as layouts, colors, fonts, images, icons and animations;

- Create and integrate APIs to communicate the website or application with external services or other system components;

- Use version control tools, such as Git, to manage source code and collaborate with other developers;

- Use automated testing and code quality tools to verify code functionality, coverage and compliance;

- Use web frameworks and libraries, such as Bootstrap, React, Angular, Vue, etc., to facilitate development and increase productivity;

- Use agile methodologies, such as Scrum and Kanban, to organize teamwork and deliver value to the customer;

- Learn and apply emerging technologies, such as responsive design, progressive web apps, web components, etc., to improve the user experience on different devices and platforms.