Can't figure out the right way to use rotation of proxies within a script to speed up the execution process

I've created a script using python implementing rotation of proxies within it to fetch correct response from some links. This function get_proxy_list() produces proxies from a source. However, I've hardcoded 5 proxies within that function for brevity.

Now, you can see there are two more functions validate_proxies() and fetch_response(). This function validate_proxies() filters out working proxies from the list of crude proxies generated by get_proxy_list().

Finally, this function fetch_response() uses those working proxies to fetch correct response from the list of urls I've.

I don't know whether this function validate_proxies() should be of any use at all because I can use those crude proxies directly within fetch_response(). Moreover, most of the free proxies are short-lived, so by the time I try to filter out those crude proxies, the working proxies are already dead. However, the script runs very slowly even when it finds and uses working proxies.

I've tried with:

import random
import requests
from bs4 import BeautifulSoup

validation_link = 'https://icanhazip.com/'

target_links = [
    'https://stackoverflow.com/questions/tagged/web-scraping',
    'https://stackoverflow.com/questions/tagged/vba',
    'https://stackoverflow.com/questions/tagged/java'
]

working_proxies = []

headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.150 Safari/537.36'
}

def get_proxy_list():
    proxy_list = ['198.24.171.26:8001','187.130.139.197:8080','159.197.128.8:3128','119.28.56.116:808','85.15.152.39:3128']
    return proxy_list


def validate_proxies(proxies,link):
    proxy_url = proxies.pop(random.randrange(len(proxies)))
    while True:
        proxy = {'https': f'http://{proxy_url}'}
        try:
            res = requests.get(link,proxies=proxy,headers=headers,timeout=5)
            assert res.status_code==200
            working_proxies.append(proxy_url)
            if not proxies: break
            proxy_url = proxies.pop(random.randrange(len(proxies)))
        except Exception as e:
            print("error raised as:",str(e))
            if not proxies: break
            proxy_url = proxies.pop(random.randrange(len(proxies)))

    return working_proxies


def fetch_response(proxies,url):
    proxy_url = proxies.pop(random.randrange(len(proxies)))

    while True:
        proxy = {'https': f'http://{proxy_url}'}
        try:
            resp = requests.get(url, proxies=proxy, headers=headers, timeout=7)
            assert resp.status_code==200
            return resp
        except Exception as e:
            print("error thrown as:",str(e))
            if not proxies: return 
            proxy_url = proxies.pop(random.randrange(len(proxies)))


if __name__ == '__main__':
    proxies = get_proxy_list()
    working_proxy_list = validate_proxies(proxies,validation_link)

    print("working proxy list:",working_proxy_list)

    for target_link in target_links:
        print(fetch_response(working_proxy_list,target_link))

Question: what is the right way to use rotation of proxies within a script in order to make the execution faster?

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