I was a back-end Software Engineer at uMed in 2018.
The back end is Python, built on Django and Django REST Framework, with PostgreSQL behind it and Celery and Redis handling work that shouldn’t happen inside a request.
It ran on AWS, deployed with Ansible and Docker, with some of the work moved out to Lambda.
Django and Django REST Framework are still a sensible choice for a back end that is mostly a well-modelled database with an API over it, which is what a lot of products need first.