The error beacon arrives with a screenshot of the page

Your frontend's window.onerror posts to an exec endpoint with the message, the stack, and the URL the user was on.

The script does one more thing. It asks the browser service for screenshot?url= of that same URL at the user's reported viewport, waits for it, and writes the PNG next to the JSON in the files service under the error's hash. The error list you read in the morning has a thumbnail column. Half the time you know what broke before you read the trace, because the layout is visibly wrong in the picture.

Errors that fire on a logged-in page get the cookie-injected instance. No Sentry replay tier, no rrweb bundle shipped to users.

Every error report used to be a stack trace. Now it's a stack trace and a photo.