Communicate between a python server and node server
After much research, I felt like having two local applications running on different ports is a little impractical or rather more complicated than it should be. 
As such, I have migrated my project to use Django instead of using React JS and integrate it with python. This way Django's back-end can handle the POST requests I make and update the DOM as needed. 
All this is for a chatbot application that is suppose take a user's question, call Amazon's Lex for a intent and entity which then spaCy, a ML framework, searches our database for an answer. The answer is then returned and the DOM is then updated without refreshing the page.
I have an application that uses two servers that need to communicate with one another. One is a python server that implements BaseHTTPRequestHandler's do_METHODs. The other is node js's development server/production server that hosts a React JS application.
The node js application uses a POST request to get a message from an input which the python server extracts that message from that POST request and then calls Amazon's Lex using Boto3 to get a response.
Whenever I run node js development server (on localhost:3000) and the python server (on localhost:3001), the python server is able to recognize that a POST request has been made and goes ahead and gets a response. However, when I run node js production server (on localhost:5000) and the python server (on localhost:3001), the node js server is unable to communicate with the python server. Why is this?