This document discusses two projects - REMICS and Cloud4Trends - that address challenges in cloud computing. REMICS develops a model-driven methodology for migrating legacy applications to cloud services and addresses interoperability issues. It focuses on providing a domain-specific language for abstracting cloud deployment complexity and solving behavioral and data interoperability. Cloud4Trends leverages cloud infrastructure for real-time trend detection in social media streams, providing a scalable solution for analyzing large-scale data. It detects variations and trends using a cloud computing service developed by the VENUS-C project.