Will shinymetrics slow down my Shiny applications?

No. All shinymetrics tracking is done asynchronously client-side (from the web browser of your users).

I cannot see any data on the dashboard

If you are on a company network make sure your application can send data to shinymetrics.com. It is likely that your IT team controls traffic to and from your Posit Connect instance and that traffic is blocked.

Is Shinymetrics GDPR compliant?

Shinymetrics is built in compliance with European GDPR law as well as Swiss law. All data is stored in Europe. All data is stored raw, it is not enriched or pre-processed. However, you need to collect consent from users of your application in order to be fully compliant.

What's the difference between "prod" and "test" data?

This toggle can be dynamically defined and is meant to be able to distinguish between data collected while developing (test) and data collected in production. This is so you do not "pollute" your actual usage data by real users with data produced by programmers as they develop the application.