Create a performance and reliability plan for the checkout stack on [Platform] targeting [Timeframe] improvements. Establish speed budgets (LCP target [LCP], TTFB, CLS), define SLIs/SLOs (availability, error rate [ErrorRate], payment latency), and instrument synthetic and RUM monitoring. Prioritize fixes (render-blocking scripts, third-party tags, server rendering, CDN caching, prefetch/prefill). Include resilience patterns: idempotent orders, retryable payment intents, circuit breakers.
Output format:
KPI table (Metric, Baseline, Target, Owner, Review Cadence).
Backlog (Issue, Root Cause, Fix, Effort, Impact).
Runbook for incidents (detect → triage → rollback) and dashboards to create.