How reliable does it work?

[pavelmaksimov]

Has it been used in production, how well does it work?

[didmar]

Hi! Yes, I'm using it in production for this web app: https://github.com/itsupera/furiganalyse
I never had any issue with it, but there is not a lot of usage on this app.
So you might want to stress-test it a bit if you are expecting a lot of traffic.