Enforcing web performance budgets in CI/CD with Sitespeed.io and Slack

Maintaining optimal website performance as new features are introduced is a challenge, notably for SaaS companies, due to performance regression that slows page loads and reduces user conversion rates. This tutorial outlines how to implement a web performance budget within a CI/CD pipeline using Sitespeed.io and Slack alerts, requiring tools such as CircleCI, GitHub, Node.js, Docker, and Vercel. The tutorial explains how to define performance budgets focusing on time-based metrics like First Contentful Paint and Largest Contentful Paint, as well as quantity-based metrics such as total page weight and HTTP requests. It details steps for integrating Sitespeed.io to enforce these budgets, deploying the project on Vercel, and automating performance checks with CircleCI, which triggers tests upon code changes and stores results as artifacts. Moreover, the guide provides instructions for setting up Slack notifications to alert teams when performance metrics exceed set thresholds, demonstrating the practical application of these concepts by adjusting the budget.json file and observing the alerts on Slack.