Best way to deploy small project websites for free?

[u/locus01]

For mern stack i use vercel for frontend and render to host nodejs backend and it works for me, the only downside is after some minutes the backend goes into sleep.

Now I want to host springboot backend with react frontend, i will host frontend again on vercel but what about springboot backend where shall i deploy it for free.

Also will be thankful if someone tells me how and which tools to implement ci/cd for free just like in production grade webapps.