Modern webapps have multiple microservices that may be on multiple domains (e.g. subdomains) and providers (e.g. both AWS and Google Cloud; or Google Container Engine Google App Engine within the Google Cloud).
Yet there are reasons to present these together. For example, Content Distribution Networks and security services are often designed to work on one (or a few domains and source platforms).
What are best practices in presenting microservices in an integrated way? Gateways? Load balancers? Or perhaps skip the integration and accept the heterogeneity?