Frontend Developer for Multilingual Web App

I'm seeking a skilled frontend developer for a web application project. The app has a unique purpose and needs to be built with a custom framework (other than the mainstream ones like React, Vue.js, or Angular).

Key Requirements:
- Expertise in creating a responsive design
- Experience in developing multi-language capabilities

Ideal Skills and Experience:
- Proficiency in a variety of frontend frameworks
- Strong understanding of responsive web design
- Experience in implementing multilingual features in a web application.

Please provide examples of previous similar projects in your application.