Currently, the API is slow because it running a free trier machine.
The first API call after a long time might timeout because if the API is not used for while the free tier suspends the API

If the demand is able to pay for a non-free tier environment. I will deploy accordingly

FYI: https://www.reddit.com/r/webdev/comments/8poyxo/how_slow_is_a_cold_start_at_heroku/