Frontend Observability (RUM)

Monitor web, mobile, and hybrid frontends using Real User Monitoring with DQL. Targets the new RUM experience only — do not use classic RUM data.

Data Model

Three data sources, each for a different question:

Source	Use for	Granularity
timeseries dt.frontend.*	Trends, dashboards, alerting	Aggregated metric
fetch user.events	Root cause, individual page views / requests / clicks / errors	Per-event
fetch user.sessions	Bounce rate, session duration, session-level aggregates	Per-session

Rule of thumb: start with metrics for the shape of the problem, drill into events for the why. Use sessions when the question is about user journeys, not individual interactions.

Full event model: https://docs.dynatrace.com/docs/semantic-dictionary/model/rum/user-events

Common Filters

• frontend.name — frontend identifier (e.g. my-frontend)
• dt.rum.user_type — real_user, synthetic, robot
• dt.rum.application.type — web or mobile
• device.type, browser.name, os.name, geo.country.iso_code

Workflows

Each workflow maps to one or more references. Load the reference when you start the workflow, not upfront.

Workflow	Reference
Core Web Vitals (LCP, INP, CLS)	references/web-vitals.md
Session, bounce, engagement analysis	references/user-sessions.md
User actions — interaction lifecycle, completion reasons, timeouts	references/user-actions.md
Errors, exceptions, trace correlation	references/error-tracking.md
CSP violations — security policy enforcement and blocked resources	references/csp-violations.md
Mobile app starts, crashes, ANR, native signals	references/mobile-monitoring.md
Request latency, long tasks, JS profiling, geo performance	references/web-performance-analysis.md
Visibility changes — tab switching, background time, engagement quality	references/visibility-changes.md
Slow page load — backend vs render vs network vs JS triage	references/slow-page-load-playbook.md
Diagnosing zero results, anomalies, ambiguous data	references/troubleshooting.md

Performance Thresholds (quick reference)

• LCP: Good < 2.5 s

  Poor > 4.0 s

• INP: Good < 200 ms

  Poor > 500 ms

• CLS: Good < 0.1

  Poor > 0.25

• Mobile cold start: Good < 3 s

  Poor > 5 s

• Long tasks: > 50 ms problematic, > 250 ms severe

When to Use

Use this skill for real-user web, mobile, or hybrid frontend telemetry — Core Web Vitals, sessions, clicks, errors, crashes, request latency from the browser/app, and frontend↔backend trace correlation.

Use a different skill for:

• Synthetic monitors / availability checks → dt-obs-synthetic
• Backend services, traces, spans → dt-obs-services, dt-obs-tracing
• Infrastructure, hosts → dt-obs-hosts
• Logs → dt-obs-logs
• Problems and incidents → dt-obs-problems