My startup Meshcloud [0] is helping companies manage the "organizational" side of multi-cloud like integrating account provisioning, SSO, policies, chargeback, quotas etc. using a declarative orchestration approach we call "org as code" (basically infrastructure as code but for org stuff). Our product is e.g. used by a large german car manufacturer to orchestrate hundreds of tenants across AWS, Azure and a mix of private Clouds based on OpenStack, Kubernetes and Cloud Foundry. Workload orchestration is obviously the next challenge down the road for these customers, so we're currently looking at providing good integration to tools like Open Service Broker API, Terraform, Bosh, Spinnaker etc. Each of those solves a slightly different set of problems but at the scale our customers are operating at they all have their place.