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.

NOTE:
My terms would need extended support for about 30-45 days to make sure the fixes stick during live traffic.
Also, as mentioned above, the work would be done remotely on the provided server with remote access. I have no interest in copying your work but for security reasons cannot allow copying of the code outside.

Thanks.