MetricKit Collect aggregated performance metrics and crash diagnostics from production devices using MetricKit. The framework delivers daily metric payloads (CPU, memory, launch time, hang rate, animation hitches, network usage) and diagnostic payloads (crashes, hangs, disk-write exceptions) with call-stack trees for triage. Contents - Subscriber Setup - Receiving Metric Payloads - Receiving Diagnostic Payloads - Key Metrics - Call Stack Trees - Custom Signpost Metrics - Exporting and Uploading Payloads - Extended Launch Measurement - Xcode Organizer Integration - Scope Boundaries - Common Mi…