Golang and javascript programmer to update an existing application

We seek a developer to update our application. Most of the updates will concern the frontend (javascript/react), but some changes to the backend (Golang) may also be required. The project concerns a solar cell panel where a user can place solar panels on their roof, the updates include a refinement of the solar panel selection and overall design improvements, as well as some improvements to the backend. It could be possible to rewrite the project to another JS framework such as Mirthril or Vue if the developer prefers it, it is currently written in react. The project may be continued with further tasks if the collaboration goes well.