Which development environment would be best for a website

Hi everyone, I have been looking for requirements about the project that I will work on. I have jitsi meet on my cloud server and it works perfectly but jitsi meet only will be my streaming service. I will process data which comes from jitsi meet. The project is going to a website and also I want to make it mobile compatible as well.

My question is: which programming languages shall I use that provides best efficacy and efficiency on both frontend and backend.

Thank you in advance.