Performance and Observability

Professional Track: Complete this lesson with a working implementation, architecture notes, and a documented trade-off decision.

Overview

Performance work without observability is guesswork. Professional Vue teams define measurable targets, collect production telemetry, and optimize only where impact is verified.

Metrics Model

Core Web Vitals

  • LCP: largest content load speed.
  • INP: interaction responsiveness.
  • CLS: layout stability.

Engineering metrics

  • JavaScript bundle size per route.
  • API latency percentiles.
  • Frontend error rate and affected sessions.

Measurement Pipeline

Lab vs field data

Use lab tools for repeatable local profiling and field telemetry for real-user behavior validation.

Instrumentation example

window.addEventListener('error', (event) => {
  telemetry.capture('frontend_error', {
    message: event.message,
    path: location.pathname
  })
})

Optimization Strategy

Bundle and route splitting

  • Split route-level code with lazy imports.
  • Defer non-critical widgets and analytics bootstraps.
  • Set per-route bundle budgets in CI checks.

Render optimization

Minimize reactive dependencies in high-frequency updates and avoid unnecessary deep watchers.

Learning Objectives

  • Apply code splitting and lazy loading by route.
  • Track Core Web Vitals and front-end errors.
  • Set budgets and performance gates in CI.

Common Mistakes

  • Optimizing based on intuition instead of measured bottlenecks.
  • Tracking only build-time metrics and ignoring runtime user experience.
  • No alerting thresholds for regressions in production.

Engineering Notes

Define SLO-like frontend goals: target vitals percentiles, acceptable error budgets, and response playbook when thresholds are breached.

Practice Scope

Deliver one production-style mini-feature, include implementation notes, and record one performance, reliability, or maintainability trade-off in your commit summary.

Back to roadmap: Vue Roadmap