A good language for developing a smart assessment web app?

I would like to work on a web app that provides multiple formative assessments, and provides personalized feedback with a custom image denoting different areas needing improvement, what topics went well, etc.

I would also like basic e-commerce functionality like user accounts, payment history, and things like that. What would be a good language for such a project? If I'm asking this question, I know I should probably find a professional, but I'm wondering what language(s) front/back would be a proper fit for tackling this problem? I know there's not one correct choice, but what would be a practical, efficient combination? Just for my own edification :) and thanks in advance!