Javascript development and expertise to support client

I am seeking assistance from a Junior Javascript expert to support a project for a client. Specifically, the right professional will have the knowledge and experience necessary to provide both front-end and back-end web development to create an new platform. Additionally, an existing codebase needs to be assessed. Finally, the project is expected to take more than three months to complete. If you have the skills and experience to meet these requirements, please let me know.