Enterprise Application UI / Vanilla JS (ES6, WebComponents)

We are a start-up and searching for support in our UI development. We are building (big) enterprise applications. Our backend provides JSON REST WebServices that are consumed by our frontend in ES6 with WebComponents (based on MDN and lit-html) - Vanilla JS. In a first step it's the following job: Migrate a pure ES6 application (only JS with self-written renderer and binding functionality and Bootstrap4 template) to a pure ES6 application based on WebComponents and lit-html (again with BS4 for templating). The technical infrastructure is already given ("how the application" should work; principal architecture). Therefore, it's not a real migration, it's more a rebuild from scratch where you can have a look to the 'old' application and use them as a kind of requirement description. The rebuild will take some weeks that will be payed on a time and material basis. But of course, before we start, I would like to know more about your JS developer skills. Therefore, before we will start, I will ask you for doing a very small test task to have a better feeling how you work. If this project works fine, I'm looking forward to offer you more jobs like this / also with a higher daily rate.