Why this workshop?
Event-Driven Architecture is easy to sell and hard to get right.
In this workshop we go beyond buzzwords and design systems that actually survive production: duplicates, retries, races, schema changes, and human mistakes. You’ll redesign real flows, argue architectural trade-offs, and dissect failure stories from systems that looked right on paper and still broke.
If you’ve ever wondered whether Event-Driven Architectures (EDA) is the right choice—or feared you might be using it wrong—this workshop is for you.
Objectives
Learn when EDA actually helps — and when it quietly destroys systems
Make architecture decisions you can defend (trade-offs, not dogma)
Leave with practical patterns you can apply Monday
Who is it for?
Software architects & senior engineers designing distributed systems
Teams already using Kafka or other message brokers and feeling the pain
People who enjoy challenging assumptions and debating architecture choices
What to expect?
Hands-on examples of idiomatic code patterns
Highly interactive debates, live redesigns, and uncomfortable questions
Hard trade-offs pictured with both diagrams and code
Real-world stories: what worked, what broke, why, and how it was fixed
Technical requirements (nice to have):
IntelliJ Ultimate or Community
Unrestricted access to GitHub & Maven Central
Maven
Agenda
Introduction & Core Concepts
Why EDA: resilience, extensibility, scalability, auditability
When not to use EDA
EDA Levels
Event vs Command vs Query? Calls vs Messages?
Brokers: Kafka mental model (topics, partitions, offsets)
Why EDA: resilience, extensibility, scalability, auditability
When not to use EDA
EDA Levels
Event vs Command vs Query? Calls vs Messages?
Brokers: Kafka mental model (topics, partitions, offsets)
Designing with Events
Event Storming (lightweight)
Event-Carried State Transfer vs Notification
Delta vs Snapshot Event
Event Granularity: Internal (domain) vs External (integration)
Event Metadata
Exercise: Redesign a REST API orchestration to an Event-based choreography
Event Storming (lightweight)
Event-Carried State Transfer vs Notification
Delta vs Snapshot Event
Event Granularity: Internal (domain) vs External (integration)
Event Metadata
Exercise: Redesign a REST API orchestration to an Event-based choreography
Hands-on: build an event flow with Spring Kafka
Produce -> Consume -> React
Idempotency, Retries
Integration Testing techniques for Producer & Consumer
Produce -> Consume -> React
Idempotency, Retries
Integration Testing techniques for Producer & Consumer
Hard Problems
Duplicate Messages
Racing and Out-of-order Messages in consumer
Consumer callback race
Transactions, Outbox Pattern, CDC
Eventual Consistency via Compensations, Reservations, and Saga Pattern
Poison-pill message and message loop
Request-Apply (Anti)Pattern
- Privacy & Security
Event Schema Evolution
Duplicate Messages
Racing and Out-of-order Messages in consumer
Consumer callback race
Transactions, Outbox Pattern, CDC
Eventual Consistency via Compensations, Reservations, and Saga Pattern
Poison-pill message and message loop
Request-Apply (Anti)Pattern
Event Schema Evolution
Wrap-up
Architecture Tradeoffs & War storiesbility
When EDA failed (and why)
Decision chcklist for real projects
Key takeaways
Architecture Tradeoffs & War storiesbility
When EDA failed (and why)
Decision chcklist for real projects
Key takeaways
Who are the trainers?
VICTOR RENTEA
Java Champion & Independent Trainer
VICTOR RENTEA CONSULTING
With 20 years of experience, Victor is a Java Champion specializing in training software developers and architects. Thousands of engineers from over 150 companies have attended Victor’s workshops, enabling him to develop deep insights across a variety of application domains. Distilling the lessons learned from these sessions, he gave countless educational yet entertaining talks at top conferences, where he’s known as ‘the speaker with the soundboard’. In his spare time, Victor coaches individuals and teams and organizes online meetups for the European Software Crafters community. More on https://victorrentea.ro
