$ pip3 install -r requirements.txt

$ FLASK_APP=flask_psycopg flask run
$ wrk http://localhost:5000

$ gunicorn -w 1 --bind 0.0.0.0:5000 flask_psycopg:app
$ wrk http://localhost:5000

$ gunicorn -w 4 --bind 0.0.0.0:5000 flask_psycopg:app
$ wrk http://localhost:5000