After many years of running on Heroku, Replit has fully migrated to Google Cloud Platform with the goal of achieving greater flexibility and control over its infrastructure to support its mission of bringing a billion software creators online. The migration involved four stages: demoing a prototype, migrating data from Postgres to self-hosted databases in Google Cloud, moving to Google Cloud SQL for Postgres administration offloading, and finally, moving the front-end to utilize the Cloudflare Load Balancer's controls to redirect requests based on percentage. The migration was a significant project requiring extensive planning and practice to ensure a seamless experience for users, with the team rehearsing failure modes multiple times and using tools like Redis Labs' Google Cloud marketplace product to validate their strategy.