Below are some of the responsibilities a React.js developer is expected to assume in their position:  
- Maintain existing React systems, including fixing bugs
 - Design and develop new custom components to meet project requirements
 - Install and configure server environments for React deployments
 - Maintain and update project dependencies as well as fix any conflicts
 - Working with other JavaScript developers and software engineers to develop front-end and back-end architecture that’s well structured and flexible, along with the APIs to support it