Event Storming Vocabulary

Event storming is exactly this: it is a collaborative workshop where domain experts and developers cover a wall with sticky notes representing domain events, arranged in the order they actually happen, to surface a business process's real workflow, including its edge cases and disagreements, before any code is written. A hash collision is an unrelated hash-table concept about two keys sharing a bucket. This surface-the-real-workflow-collaboratively approach is exactly why event storming catches process misunderstandings before they get baked into code.

Event storming here provides early surfacing of process disagreements and edge cases, since arranging domain events together on a wall forces every participant's understanding of the workflow into the open before code encodes any one person's incomplete assumption. One developer writing the workflow alone from their own understanding has no mechanism to catch a domain expert's silent disagreement about how the process actually works. This surface-disagreements-together behavior is exactly why event storming is run before building features for complex or poorly understood business processes.

This is a missed event-storming opportunity, since running a collaborative workshop to lay out the actual domain events would have surfaced disagreements or gaps in the developer's understanding before the code was written. A cache eviction policy is an unrelated concept about discarded cache entries. This built-from-solo-understanding pattern is exactly the kind of risk a reviewer flags once a business process is complex enough that no single person is likely to understand it completely.

Running an event-storming workshop with domain experts confirms the actual sequence of domain events, including when a refund can occur, collaboratively before any code is written. Continuing to build features entirely from one developer's own understanding of the process regardless of how often a wrong assumption ships to production is exactly what caused the incorrect refund logic described in this incident. This collaborative-workshop approach is the standard fix once a business process is confirmed complex enough to hide a wrong solo assumption.

Event storming gets every participant's understanding of the process into the open at the same time, catching disagreements and edge cases through discussion, while a single domain expert's written document reflects only one person's understanding and gives developers no way to catch a gap or disagreement that a group discussion would have surfaced. This is exactly why event storming is preferred for complex or poorly understood processes, while a written document remains useful mainly as a reference after the actual process has already been confirmed.