Ask HN: What tools would you use to build in-app analytics?

[keydunov]

I am working on an open source project, which I hope would be useful down the road. But, now I’m trying to dig into landscape what tools currently exist and used for building customer-facing analytics into an app.

Say, you are building a B2B SaaS app, which would have some reporting and dashboarding. What would you use? What fronted libraries, backend framework/libraries, database, etc.?

Thanks!