>I'll probably migrate to some proof-of-work based schemes and some algorithms to detect anomalous requests, but it would require some engineering work on my pa

>I'll probably migrate to some proof-of-work based schemes and some algorithms to detect anomalous requests, but it would require some engineering work on my part Have you tried mcaptcha? https://github.com/mCaptcha/mCaptcha https://github.com/mCaptcha/mCaptcha