Ably has developed a distributed real-time messaging platform and outlines the essential skills and knowledge for a distributed systems engineer. Key areas of expertise include distinguishing between microservices and truly distributed systems, understanding hash rings, and grasping the significance of gossip protocols and consensus algorithms, which are crucial for maintaining real-time state changes in distributed environments. Engineers must also navigate the trade-offs between consistency and availability, often opting for eventual consistency through conflict-free replicated data types, and must possess a deep understanding of networking protocols across all layers, including HTTP, WebSockets, and TCP. Ably emphasizes that a solid foundation in systems engineering, including programming, design patterns, and infrastructure management, is vital for tackling the challenges inherent in global distributed systems. The company offers cloud infrastructure and APIs to aid developers in creating scalable real-time applications and is actively expanding its team with multiple open positions in distributed systems engineering.