GDPR isn't really related to the infrastructure, and isn't a problem if you built your product knowing you'll need to conform. Shopify is GDPR compliant, for all merchants, and runs on Google Cloud in multiple regions.
*privacy invasive that GDPR is explicitly set up to make harder, so duh
Also, lots of companies assert GDPR compliance via magical thinking. They most often are wholly wrong. Shopify can say whatever they want, but there’s no certification body.
Source: I’m the person who evaluates and builds compliance systems for a range of services you almost definitely use.