Performance

Budgets, measurements and hydration rules for fast XTend apps.

What it covers

XTend records loader, mount, hydration, render, route, and interaction work as versioned measurements. A budget belongs to a named phase and time base; a large absolute timestamp must not be mistaken for navigation duration.

Public building blocks

• fabric/xtend-fabric.js collects fiber and component measurements.
• tests/performance/performance_regression_suite.js checks deterministic budget cases.
• xtend.performance.measurement.v1 uses pass, warn, and fail status values.

Recommended workflow

Run regression and Fabric measurement together:

node scripts/run_xtend_tests.js performance-regression fabric-performance-measurements --json

Read phase, actual value, budget, and status first. Fix a fail in the affected work; change a budget only when the documented user requirement changed. Build trends from comparable samples, never timestamps with different origins.

Next steps

• XTend DEV API
• Hydration Policies
• A11y Keyboard Smokes