Throughout my 15+ years in software development, I have helped automating highly scalable core workflows at global companies including T-Mobile, Lufthansa and Zalando. I have contributed to various open source workflow engines. I am co-founder and chief technologist of Camunda, an open source software company reinventing workflow automation. I co-authored "Real-Life BPMN," a popular book about workflow modeling and automation. I regularly speak at conferences and write for various magazines. I am currently focused on new workflow automation paradigms that fit into modern architectures around distributed systems, microservices, domain-driven design, event-driven architecture and reactive systems.
Event-driven architectures enable nicely decoupled microservices and are fundamental for decentral data management. However, using peer-to-peer event chains to implement complex end-to-end logic crossing service boundaries can accidentally increase coupling. Extracting such business logic into dedicated services reduces coupling and allows to keep sight of larger-scale flows - without violating bounded contexts, harming service autonomy or introducing god services. Service boundaries get clearer and service APIs get smarter by focusing on their potentially long running nature. I will demonstrate how the new generation of lightweight and highly-scalable state machines ease the implementation of long running services. Based on my real-life experiences, I will share how to handle complex logic and flows which require proper reactions on failures, timeouts and compensating actions and provide guidance backed by code examples to illustrate alternative approaches.