Modifying an existing website on django package

I have a website in working condition made using django package in python3.

I need to fix a couple of bugs, modify the website to be screen size/type adaptive responsive and then fully deploy it online, after doing pre-deployment test and overview for any abnormalities.

I already have old website up and running and will deploy on the same domain and server.

Since this is a serious project, I would appreciate if you can give examples of your experience in working with same platform and package and not only web dev or python and I would be expecting a level of professionalism in executing the work.

Thanks.