Developing and deploying transactional cloud applications such as banking and e-commerce systems is a daunting task for developers. The reason for this difficulty is twofold. First, developing such applications shifts the developers’ focus from the application logic to considerations of distributed transactions, fault-tolerance, consistency, and scalability. Second, deploying such applications involves multiple systems, such as databases, load balancers, or containerized services, impeding efficient resource management. This demonstration presents Styx, a scalable application runtime that allows developers to build scalable and transactional cloud applications with minimal effort. It supports serializability and exactly-once guarantees and focuses on the ease of development and deployment, as well as Styx’s fault-tolerance mechanisms.