Answer
Downtime is minimized through careful DNS management, staged data migration, pre-launch validation, and a documented cutover sequence. It's a better idea to execute your migration process in phases, rather than making the jump in one go. Phased replatforming means choosing a non-critical microservice and moving that over to the new platform in an initial migration phase. You can test the module in its new environment to ensure everything is working, and if it is, you can begin a second phase in which more parts of the website are moved over. Eventually you can move over the critical parts of your website, safe in the knowledge that you've ironed out the hazards.
Organizations can minimize downtime during application migration and validation by using techniques such as "blue-green" deployments, canary releases, or traffic mirroring. Your application continues to serve users while the workloads are being migrated, which minimizes disruption and downtime. The downtime depends on your cutover strategy.