Capturing PostHog Events in Rails Without the Footguns

PostHog's Ruby SDK does what it promises. You call posthog.capture, pass a distinct ID and an event name, and data arrives in your dashboard. The getting-started guide takes five minutes. The next six months of living with it take considerably longer.

The gap between "PostHog works" and "PostHog works well in a Rails app that processes mortgage applications" is where most teams lose time. Not because the SDK is bad — it's fine — but because the integration patterns that feel natural in a Rails controller are almost never the ones you want in production. I have spent more hours than I'd like debugging silent event loss, duplicated captures, and properties that looked right in development but arrived mangled in production because of ActiveRecord serialization quirks.