Just a little scriptlet that runs a frontend (in this case, node) web server alongside a backend (in this case, python) server. This should not be used in production unless otherwise proven.

servers.py

#!/usr/bin/env python
import subprocess
import socket
from multiprocessing import Process
import sys

if sys.version_info < (3,):
    range = xrange

BIND_IP = '0.0.0.0'
processes = []


def get_port():
    start_port = 5000
    end_port = 6000

    def test_bind(port):
        """ Test a bind to the given socket so we can make run more gooder, 'influenced' from werkzeug's bind_simple """
        test_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        test_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        test_socket.bind((BIND_IP, port))
        test_socket.close()

    for portnum in range(start_port, end_port, 2):
        try:
            test_bind(portnum)
            test_bind(portnum + 1)
            return portnum
        except socket.error:
            pass
    raise Exception("No port is open between {} and {}, try something else?".format(start_port, end_port))


def watch_process(command_list):
    process = subprocess.Popen(command_list, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)

    try:
        # Poll process for new output until finished
        while True:
            nextline = process.stdout.readline()
            if nextline == '' and process.poll() != None:
                break
            sys.stdout.write(nextline)
            sys.stdout.flush()
    except:
        #exit without garbaging up my garbage
        pass


def start_backend(portnum):
    print("Starting Flask at port {}".format(portnum))
    watch_process(['python', 'backend.py', str(portnum)])


def start_frontend(portnum):
    print("Starting Express at port {}".format(portnum))
    watch_process(['node', 'frontend.js', str(portnum)])


if __name__ == '__main__':
    port = get_port()

    p = Process(target=start_backend, args=(port,))
    p.deamon = True
    p.start()

    p1 = Process(target=start_frontend, args=(port + 1,))
    p1.deamon = True
    p1.start()

    try:
        p.join()
        p1.join()
    except KeyboardInterrupt:
        print("\rWe understand that you have a choice when running servers and are thrilled that you chose SERVERNAMEHERE.  Shutting down now!")