Gatsby has introduced powerful open source features that allow massive build speed improvements for sites with lots of images. By using Google Cloud services such as Pub/Sub, Cloud Storage, and Cloud Functions, users can set up parallel image processing to significantly reduce build times. The process involves enabling the required services on Google Cloud, deploying the necessary services, updating Netlify sites to use gatsby-parallel-runner, and triggering a new build to test the improved performance. This tutorial demonstrates how to implement gatsby-parallel-runner to make image-heavy Gatsby builds nearly 2× faster, with a notable 47% drop in build times on a demo site.