# CloudWatch RUM Checklist (July 2026)

## When RUM is the right tool

- [ ] You need **real-user** browser performance (LCP, CLS, INP) not just server latency
- [ ] You accept sampling — 100% session capture is usually unnecessary and costly
- [ ] Privacy / cookie consent reviewed for your jurisdictions

## When NOT to use RUM alone

- [ ] You only need API/backend SLOs → Application Signals + Synthetics
- [ ] You need deep session replay / product analytics → dedicated vendor may still win
- [ ] Server-side only workloads (no browser)

## Setup checklist

- [ ] App monitor created in each Region users hit
- [ ] Snippet / npm package version pinned
- [ ] Cognito identity pool or auth mode documented
- [ ] Allow-listed domains only
- [ ] Sampling rate set (start low, raise if gaps)
- [ ] CloudWatch alarms on Core Web Vitals thresholds with owners
- [ ] Correlate slow pages with Application Signals backend SLOs for the same journey

## Cost worksheet

| Input | Value |
| --- | --- |
| Sessions / month (estimated) | |
| Events per session (avg) | |
| Sampling % | |
| Effective events / month | sessions × events × sampling |

Confirm current RUM event pricing on [CloudWatch pricing](https://aws.amazon.com/cloudwatch/pricing/). Re-check after traffic spikes or marketing campaigns.

## Privacy

- [ ] PII scrubbing for URLs and custom attributes
- [ ] Consent banner integration where required
- [ ] Retention aligned with security policy