Explore the concept of stateful systems and sagas in this 58-minute conference talk from NDC Oslo. Delve into the misconceptions surrounding stateless design and discover how complex software systems require collaborative processing. Learn about modeling long business transactions, distributed resources, and eventual consistency without relying on distributed transactions. Examine the role of sagas in designing fault-tolerant systems, and gain insights into implementing process managers, domain experts, and autonomy. Investigate practical examples, potential pitfalls, and key takeaways for effectively utilizing sagas in complex collaborative domains.