Hello, just to confirm, is GrowthBook integration with google analytics 4 handled on sdk side? Do we able to run experiment on back-end(for example new ML model) and see results of impact on user engagement/retention in google analytics 4 events?

Our SDKs are event tracking agnostic, but GA4 is very common. As long as you have a consistent user identifier attribute present on both frontend and backend, you can run your experiments in both environments and measure across the stack. To measure GA4 events on the backend you may want look into something like GA4's Measurement Protocol

@happy-autumn-40938 so it will be able to send FF evaluation even trough Measurement Protocol to the GA4 from backend? Like described here https://docs.growthbook.io/guide/GA4-google-analytics#running-experiments-with-growthbook-and-ga4

yes, just as long as you've set up your SDK's

trackingCallback

to POST to GA