I built Phinxer for my own use a year or so ago because existing alternatives felt bad to use (Google Analytics) becasue of excessive tracking or were really expensive. I was running an app that had ~350k pageviews at the time but was only making $80 from ads so paying $50 a month for analytics sounded silly.
The actual cost of running this is only a fraction of that, so I'm now releasing the tool I wish I had found back then. It's significantly cheaper than all web analytics alternatives at $10 per 1M events that don't expire. So if you use less than 1M events you can use the events for up to a year (alternatives cost $60-$140/mo for the same volume).
Phinxer is also open source! It's built with an Express backend, React app, Postgres for general data and ClickHouse for events. I used [Vike](https://vike.dev/) which is based in Vite for this project and was very pleasantly surprised, it's what I always wished Next.js was.
Code here: https://github.com/gnardini/analytics