When deploying a service across multiple regions with substantial resource requirements, what should you validate first?

When deploying a service across multiple regions, especially when there are substantial resource requirements, it is crucial to validate that the resource requirements are within the available project quota limits. Quotas serve as safeguards to prevent excessive usage of resources, which can help maintain system stability and prevent unintentional overages that could lead to increased costs or service disruptions.

Understanding the quota limits before proceeding with deployment ensures that you do not encounter issues later on, such as being unable to allocate the necessary resources due to reaching your project's limits. This validation step is foundational and must be addressed early in the deployment process to facilitate smooth scaling and performance across different regions.

The other options focus on monitoring tools, specific machine types, or internal load balancers, but these considerations become relevant after you have ensured that your deployment is feasible within the constraints of your existing quotas. Without confirming your project's capacity to handle the resource demands, you may face roadblocks that prevent successful service deployment.