Speed optimisation is crucial for a Magento website as it directly impacts user experience, conversions, and search engine rankings. You should prepare your server so it is set-up to use compression and caching functionality including a CDN (Content Delivery Network) and Gzip compression. Ensure your images are served using next generation formats. Make sure Magento is set-up to use full-page caching and your CSS and JavaScript files are properly minified. Keep the number of extensions installed to a minimum and continually monitor your website for performance and updates.