Here's a little something similar I whipped up using Flask (Python):

    import time
    from flask import Flask, make_response, request
    app = Flask(__name__)

    @app.route('/<int:status_code>')
    def return_status(status_code):
        response = make_response()
        response.status_code = status_code
        response.data = response.status
    
        sleep = request.args.get('sleep', None)
        if sleep is not None:
            time.sleep(int(sleep))
        return response

    if __name__ == '__main__':
        app.run(debug=True)

With a handy little feature, a "sleep" query string param that'll delay the response for the given number of seconds, which I've used to test how a client handles latency etc.

[BTW, looks like you're the Elliot Carlson I used to work with way back when. Hope life is treating you well these days! :)]