Explore the world of asynchronous distributed systems in this comprehensive conference talk from NDC London 2021. Delve into the advantages and disadvantages of synchronous versus asynchronous microservice architectures, and learn when and how to transition between them. Discover key asynchronous system patterns such as CQRS, Event Sourcing, and Data Busses. Gain insights into scalability, availability, and observability differences between these architectures. Understand how to gradually evolve towards an asynchronous model without disrupting business operations. Examine various use-cases, messaging technologies, and crucial concepts like the CAP Theorem in microservices, delivery guarantees, and error handling. Master techniques for managing distributed systems, including transactional outbox, successful saga, and compensatory transactions.