Analytics
Tools that track how users interact with your application, helping you understand behavior, find problems, and measure growth.
Analytics tools record what users do in your application: which pages they visit, which buttons they click, where they drop off in a funnel, and how long they spend on each screen. This data drives product decisions.
Popular tools include PostHog (open-source, self-hostable), Google Analytics, Mixpanel, and Amplitude. Most work by adding a small tracking script to your app that automatically captures page views and click events. You can also fire custom events for specific actions ("user completed lesson," "user upgraded to paid").
For vibe coders, analytics is how you measure whether the features AI helped you build are actually being used. Setting up basic event tracking before launch gives you data from day one. AI can generate the tracking code and custom event definitions, but choosing which metrics matter (retention, activation, conversion) requires product thinking.