CQRS & Event Sourcing at OLX after year on production

on YouTube ↗36m

" summary

An engineer describes OLX’s experience running a CQRS (Command Query Responsibility Segregation) and Event Sourcing system in production for a year, covering the practical problems encountered and lessons learned. The talk discusses implementation details and operational considerations of using CQRS/Event Sourcing in a PHP-centered environment at OLX.

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" chapters (14)

1. 0:00Intro
2. 0:45Command Query Responsibility Segregation
3. 2:26ensures that all changes to application state are stored as a sequence of events
4. 9:32Sub Wallet Credits Sub Bonus Credits Sub Refund Credits
5. 11:157 commands 6 events
6. 13:44Auditing log whether commands were successful or not
7. 14:43Domain domain abstractions of the Broadway framework including the aggregate root, domain messages and domain events.
8. 16:06Adding Wallet Credits
9. 21:55Credits Query
10. 25:08Lessons Learned
11. 26:20Event Storming is not that easy as it sounds
12. 27:11It's not RDBM Remember about analysts
13. 29:07Code changes Events handle changes to data, what about changes to code? Implement & Reprocess
14. 32:53Performance Snapshots

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