mobile-analytics-crash-reporting-expert

license	Apache-2.0
name	mobile-analytics-crash-reporting-expert
description	Mobile analytics and crash reporting expert for Firebase, Sentry, Mixpanel, custom events, and crash symbolication. Activate on: mobile analytics, crash reporting, Firebase Analytics, Sentry mobile, Mixpanel, event tracking, crash symbolication, dSYM upload, ProGuard mapping, session replay. NOT for: server-side logging (use log-aggregation-architect), web analytics (use frontend-architect), A/B testing (use environment-config-manager).
allowed-tools	Read,Write,Edit,Bash(docker:*,kubectl:*,terraform:*,npm:*,npx:*)
category	Mobile Development
tags	["analytics","crash-reporting","sentry","firebase"]
pairs-with	[{"skill":"logging-observability","reason":"Mobile observability extends the broader logging and observability strategy"},{"skill":"app-store-submission-automator","reason":"Crash-free rate metrics impact app store ranking"}]

Mobile Analytics & Crash Reporting Expert

Expert in mobile analytics instrumentation, crash reporting with symbolication, and actionable event tracking across iOS and Android.

Decision Points

Stack Selection Decision Tree

High crash volume (>1000/day) OR complex error debugging needed?
├─ YES: Choose Sentry
│   ├─ Need user sessions? → Add Sentry Session Replay
│   └─ Enterprise budget? → Consider Bugsnag for enterprise features
│
└─ NO: Evaluate based on primary use case
    ├─ Need product analytics + basic crashes? → Firebase (free tier generous)
    ├─ Advanced funnel analysis required? → Mixpanel + Crashlytics
    └─ Real-time user behavior insights? → Amplitude + Sentry

Budget considerations:
├─ <$50/month: Firebase Analytics + Crashlytics
├─ $50-500/month: Sentry Team + basic product analytics
└─ $500+/month: Full stack (Sentry + Mixpanel/Amplitude)

Sample Rate Tuning

Production traffic volume:
├─ <1K daily sessions:
│   ├─ Crash sampling: 100%
│   ├─ Transaction tracing: 50%
│   └─ Session replay: 25%
│
├─ 1K-10K daily sessions:
│   ├─ Crash sampling: 100%
│   ├─ Transaction tracing: 20%
│   └─ Session replay: 10%
│
└─ >10K daily sessions:
    ├─ Crash sampling: 100% (never sample crashes)
    ├─ Transaction tracing: 5-10%
    └─ Session replay: 1-5%

Cost optimization triggers:
├─ Monthly bill >$200 → Reduce transaction sampling by 50%
├─ Storage quota exceeded → Lower session replay rate
└─ Performance impact detected → Disable replay in low-memory scenarios

Error Volume Handling

Incoming crash rate assessment:
├─ <0.1% of sessions → Normal monitoring, weekly review
├─ 0.1-1% of sessions → Daily triage, investigate top 3 crashes
├─ 1-5% of sessions → Emergency mode: stop releases, hotfix priority
└─ >5% of sessions → App store removal risk, immediate rollback

Symbolication status check:
├─ Symbolicated within 5 minutes → Continue normal flow
├─ Pending 5-30 minutes → Check CI upload job status
└─ Missing after 30 minutes → Manual dSYM/mapping upload required

Failure Modes

1. "Symbol Upload Amnesia"

Detection: Stack traces show memory addresses (0x1a2b3c4d) instead of function names Diagnosis: dSYM/ProGuard mapping upload failed or incomplete Fix:

• Check CI upload job logs for failures
• Manually upload: sentry-cli upload-dif --org X --project Y ./dSYMs/
• Verify upload: sentry-cli releases files <version> list

2. "PII Leak Catastrophe"

Detection: Analytics events contain email addresses, phone numbers, or names in Sentry dashboard Diagnosis: Missing or broken data scrubbing rules