Engineering the Future of Software
18-19 October 2016: Training
19-21 October 2016: Tutorials & Conference
London, UK

Event sourcing: The best ubiquitous pattern you've never heard of

Joe Drumgoole (MongoDB)
16:50–17:40 Thursday, 20/10/2016
Microservices, pros and cons
Location: Windsor Suite Level: Intermediate
Average rating: ****.
(4.00, 4 ratings)

What you'll learn

  • Understand the basic concepts of event sourcing and its benefits for time-based data
  • Identify the pitfalls these systems can be subject to


Event sourcing is powerful way to think about domain objects and transaction processing. Rather than persisting an object in its current state, event sourcing instead writes an immutable log of deltas (domain events) to the database. From this set of events, an object’s state is derived, at any point in the past, simply by replaying the event history sequentially.

Event sourcing is a deceptively radical idea which challenges our contemporary notions about transaction processing but is also a mature pattern with a long history. Joe Drumgoole explores how event processing is used across a spectrum of use cases, including database engines and financial systems, and compares event sourcing with Lamdba architectures to highlight the similarities between these patterns.

Photo of Joe Drumgoole

Joe Drumgoole


Joe Drumgoole is director of developer advocacy EMEA at MongoDB, where he helps developers to understand and utilize MongoDB in order to unleash the power of software and data for innovators everywhere. Joe is a software entrepreneur with over 25 years experience with successful product delivery at Digital Equipment Corporation, Nomura, Oracle Corporation, CR2, and Cape Clear Software. He is a regular speaker at technical conferences and has provided mentoring and advice to many startups over the past 10 years.