Heroku setup

• This Express server is still fucking slow! It can only handle 9.5k QPS while my Go application could handles 40k on the same machine (Mac Pro 2019, 2.6 GHz, 6-Core i7).

Other notes about FCC remote test

• The test is run right on the browser, thus, most FCC boilerplate projects need to allow request come from https://www.freecodecamp.org/ origin.

• The test is mostly rexgex matching our code to find expected patterns. This means it's very sensitive with our coding styles (your code works fine, but the test still fails). In my opinion, FCC code has terrible styles (use var instead of let or const, no blank line between app.route, if block, ...). There should be a course about coding style or general Software Engineering practices (I might contribute such course ... one day).

• localtunnel is a cool tool. It doesn't have much features like ngrok, but look likes it have a more generoues connection rate limit. On startup, the local page won't be immediately accessible (unlike ngrok). We much open the page and click the Accept button first (to declare that we know the link is serve from someone's local machine and might be dangerous). FCC in browser tests won't work until we do that.