Testing a multi-cloud app locally: LocalStack, Moto, Azurite… or one tool for all three? (opens in new tab)

If your app only talks to AWS, LocalStack is fantastic. But the moment a service reaches into GCP or Azure, local development fragments: you bolt on Moto for extra AWS bits, Azurite for Azure Blob, and the gcloud emulators for Pub/Sub and Firestore. Three+ tools, three configs, no shared state, no shared console. This post compares the options for testing a multi-cloud app locally, and introduces Vyomi — what we call a multi-cloud digital twin runtime: instead of mocking one cloud, it runs a ...