Python Code on Azure App Service running 10x slower than locally

I have a small django application that I am hosting on App Service. I noticed it runs dramatically slower on App Service than the exact same code locally. I don't see any errors and the App Services metrics don't look out of the ordinary. Any advice for how to fix this?

Here is an example function that is running 10x slower (less than 1 second for all local tests, up to 10-20 seconds on App Service).

def check_regex(voice_input, phrase, errors_allowed=4):
    print("START REGEX")
    search_str = "(%s){e<%i}" % (phrase, errors_allowed)
    regex_result = regex.search(
        search_str,
        voice_input,
        flags=regex.IGNORECASE)
    if regex_result is not None:
        print(f"REGEX CHECK: {voice_input} and {phrase}")
        print(regex_result)
        return True
    else:
        print("NO MATCH")
        return False

You can add the compile regex method outside the function block this will pre-compile the method, Remove print statements this will reduce I/O's overhead and optimize the code like below:-

# Pre-compile the regex pattern outside the function
compiled_pattern = regex.compile("({}){{e<{}}}".format(phrase, errors_allowed), flags=regex.IGNORECASE)

def check_regex(voice_input, phrase, errors_allowed=4):
    # Commented out print statements for improved performance
    # print("START REGEX")
    regex_result = compiled_pattern.search(voice_input)
    if regex_result is not None:
        # print(f"REGEX CHECK: {voice_input} and {phrase}")
        # print(regex_result)
        return True
    else:
        # print("NO MATCH")
        return False

In order to get insights on your App service running slow, Try to Monitor and inspect logs of your Web app and enable Application Insights for your Web app and get the performance graph like below:-

Enable App Service Logs like below:-

Visit Development Tools > Advanced Tool > Go > In kudu console select Current Docker logs (Download as zip) and inspect the logs, You can also call the logs below by this Rest API

One method is to select Diagnose and Solve Problems and select Availability and Performance tab to get the Logs and insight:-

Scroll down and select View solution to resolve the slow web app issue:-

Inspect Application Logs and I/O's:-