This document provides an overview of event storming, which is a technique for modeling complex business flows. It is simple, quick, and collaborative. Event storming originated from the object oriented and patterns communities and domain-driven design. It can be used for getting a quick project start, focusing on important parts, gaining an overview of business flows and architecture, and finding bottlenecks. The document describes how event storming works and what is needed to conduct an event storming session, including the right space, people, and domain events written in past tense. Event storming can be used for big picture analysis, design, UX, retrospectives, and more. Related concepts discussed include CQRS, event sourcing, and

1. EVENT
STORMINGOverview & Opportunities

2. BIG IDEA
Manifesto for Agile Software Development
Individuals and interactions over processes and tools
Working software over comprehensive documentation
Customer collaboration over contract negotiation
Responding to change over following a plan
There is value in the right,
we value on the left more.

3. HELLO
WHO AM I ?
WHO ARE YOU ?

4. “PHASE”
!
Agile
Post Phases
development

5. EVENT
STORMING
Modeling Complex Business Flows
Simple
Quick
Collaborative

6. EVENT STORMING
IS FROM …
Object Oriented Community
Patterns Community
Domain Drive Design Community
aka: DDD

7. DOMAIN DRIVEN DESIGN - DDD
2000 - Agile
2005 - Agile OO Design
Iterative Design
Focus on
Team Communication
Code Patterns
Deep Intense Understanding

9. Event Storming

10. WHAT YOU GET
…
Quick Project Start
Focus on the important parts
Overview
Business Flow
Sketch of Architecture
Outline of features to build
Find The Bottle Neck
Lean - ToC

11. EVENT STORMING NEEDS …
Right Kind of Room
Empty Walls
No chairs
Right People
Lead Developer
Biz Analyst
Sales/Marketing

12. SPACE

13. DOMAIN
EVENT IN
PAST
TENSE
Something the Domain expert cares
about

14. ITEM ADDED TO CART
PAYMENT ACCEPTED
MONTH ENDED
STOCK EXHAUSTED
SHIPMENT ARRIVED
POLICY REJECTED
BILLABLE AMOUNT
VERIFIED
Verb in past tense
Relevant to Domain Experts

15. FROM WHERE

16. BIG PICTURE - ANALYSIS - EXAMPLE

17. EVENT STORMING USED AT …
• Big Picture ( Analysis )
• Design Level ( Design )
• Value-Driven
• UX-Driven
• Retrospective

18. BIG PICTURE - JUST - THE - EVENTS

19. DESIGN LEVEL - EXAMPLE

20. THEORY OF EVERYTHING

21. CQRS - COMMAND QUERY
RESPONSIBILITY SEGREGATION
4 Letter Acronym
Impress your friends and family
Separate the Input from View
What you need is not the same as what you give
Useful
Sounds more Complicated than it is
Hard to Apply

22. EVENT SOURCING
Record input to the system as a series
of commands
Play back commands at anytime to
recreate the state of the system
Quality Implementation can get tricky

23. FUNCTIONAL
PROGRAMING
Immutable data
easier Event Sourcing
Actor Model - (Elixir - GenServer)
makes CQRS more direct
Elixir / Phoenix — Makes DDD - Bounded
Context clearer

25. ALL TOGETHER NOW
Discover Domain Events
Add
Processes
Commands
People
More Commands
Read Model / Projections
Aggregates
Optional: Event Sourcing
Implement Functional
Elixir - GenServers
Java - Scala - Akka
DDD
***
CQRS
Analysis
Design