Reports unhandled exceptions, Rails.error reports, failed ActiveJob and Sidekiq jobs, and failures the application handled, with who was affected, to Dev Bench. Fingerprints and counts in-process and sends one small request a minute; detail is uploaded only when Dev Bench asks for it, scrubbed first. Keeps recent server log lines per user action for triage, renders the browser sensor's tag, and hooks itself into Rails: bundle add devbench, bin/rails generate devbench, set DEVBENCH_DSN. Adds no dependencies beyond the standard library, never alters a response body, and never raises: a diagnostics gem that can fail a request is worse than no diagnostics.