You're Probably Doing Web Performance Wrong  with Sia Karamalegos

This podcast episode interviews Sia Karamalegos, a performance engineer, about web performance optimization. The discussion contrasts lab testing (using tools like Lighthouse) with Real User Monitoring (RUM), arguing that RUM provides more valuable insights into actual user experience by analyzing real user interactions. Sia emphasizes that while Lighthouse is useful for debugging, prioritizing RUM data helps identify and address the most impactful performance bottlenecks, improving user experience and conversion rates. She suggests focusing on metrics like First Contentful Paint, which can reveal issues like render-blocking resources, and advocates for using the Performance tab in browser DevTools for deeper analysis after identifying problems with RUM. The episode concludes with practical advice on getting started with RUM, including using readily available data sources and considering various tools or building a custom solution.