Does my droplet "sleep" when inactive?

(Why was my original question deleted after posting as “spam”? I took the time to write a carefully thought out question, and it was deleted.)

I’m noticing that the first request of the day to a personal app I’m developing on a 1GB droplet is taking an extraordinarily long time to complete. The prior night everything is fine, but it’s the initial request the following morning. (I am not shutting down the instance at night.)

Does a droplet somehow “sleep” when inactive? This is for a standard Rails/Postgres stack fronted by Nginx.

The behavior reminds me of Heroku or AWS Lambda, but I wouldn’t expect that from a VPS.

Is there something I should be looking for or checking? I can’t imagine what would cause that to happen. I’m not having any network issues or similar. The initial request completes, but only after a very long time, then everything is back to normal again.

I could add something to ping regularly, but I wouldn’t expect that to be necessary.

Any ideas? Thanks.