StriVectin improved the performance of its Gatsby-powered e-commerce site by working with Elevar to streamline the handling of third-party scripts, which are often necessary but can significantly impact site speed. By transitioning from Magento to Shopify, Elevar focused on perceived performance rather than just raw load times, employing tools like Google's Lighthouse for continual monitoring and Google Tag Manager to manage script loading. They optimized performance by evaluating the necessity and impact of each script, helping clients choose the best tools, deferring non-critical elements, and maximizing local caching. These measures helped balance business needs with performance, ensuring third-party scripts were integrated in a way that minimized their negative impact on site speed, while still meeting the business's functional requirements. This approach highlights the challenges and creative strategies in optimizing e-commerce platforms that rely heavily on third-party services.