The cloud computing paradigm has emerged as the backbone of modern price-aware scalable computing systems. Many cloud service models are competing to become the leading doorway to access the computational power of cloud providers. Recently, a novel service model, called function-as-a-service (FaaS), has been proposed, which enables users to exploit the cloud computational scalability, left out the configuration and management of huge computing infrastructures. This article discloses Fly, a domain-specific language, which aims at reconciling cloud and high-performance computing paradigms adopting a multicloud strategy by providing a powerful, effective, and pricing-efficient tool for developing scalable workflow-based scientific applications...