Java Microservices: CQRS & Event Sourcing with Kafka (Udemy.com)

Yes, the course is a good match, however it only demonstrate examples using reflection with apply method, one may restrict themselves to one approach. It would be of great pleasure to dive deep and explain to us the reason for selecting reflection as one of the existing approaches amongs other, maybe the advantage of using reflection and the downside of it.

The course is very straight forward. I used a newer version of Spring Boot and Kafka and had to adjust a few things here and there. But all in all super easy to follow and it worked great. Had some issues with Lombok and IDEA, but could also resolve that. Thank you for the course, it was very helpful and well taught!

Great course with excellent instructor who is right to the point! It was a delightful experience to code along with the instructor and learn by doing! I have setup the project with the latest Spring Boot version 3.3 with Java 21, apart from the database-platform: org.hibernate.dialect.PostgreSQLDialect in the application.yml everything in the code is still valid and works just fine! Thank you sir!

I like this course because it is a bite-sized course focusing on the key concepts of CQRS. I can easily absorb the CQRS architectural design. It covers a decent amount of contents in Kafka, MongoDB, MySQL and optimistic locking. That is fine with me because Kafka, optimistic locking and etc are not the major topics of this course.

CQRSの概要をハンズオンで学べるコースでした。 具体的に動作する実用的なサンプルがあるので、実際の現場に適用するイメージを持ちながら学ぶことが出来ました。 Q&Aにも挙がっていますが、Kafkaを含めたスケールで解決できるのは理屈上は理解できますが、イベント全体をリプレイすることには性能的にやや懐疑的なのと、mongodb側のデータ破損への言及がなかったことはやや不安でした。恐らく普通にバックアップで対応するものと思いますが。 現場への適用にはもう少し落とし込みが必要だと思いますが、CQRSを理解する第一歩としては素晴らしいコースだったと思います。

The class coding project was well-structured and straight-forward. I ran into a handful of things that didn't work as implemented in the lecture. I was implementing the code as I watched the lectures and ran into a handful of classes that just didn't work; it took some trial-and-error to figure out how to keep his clean interfaces and satisfy the compiler (I'm using Java 17 and the downloaded project uses Java 16).

The course itself is quite good, but I can not overlook that following the course to the letter, there is a problem in the order of consuming events in different queues, there is a message from the teacher 10 months ago (at the time I write this message) commenting that he will change that part of the course because it is indeed wrong, but still has not done so. It is very serious that a CQRS course where one of the main points should be to ensure that the final state of the aggregate is consistent is not fulfilled, it does not seem to me a good course.

Instructor just reads his script. Interaction with students with the video is just not there. He will code from class to class and explain the parts; however, the workflow is discussed just after all classes are implemented. He could have made the course shorter if he explained this course like what he did in module #70. Also, this is not beginner friendly as there are topics not known as a beginner.

I found the course of a very good level and speed. Loved the no-nonsense coding. - The trouble is that there has been no attention to testing at all which is a big no-no. - the other thing is that because there is no testing the code was actually wrong. Replay did not guarantee the correct order because of the multiple topics and listeners used. It does not guarantee the correct ordering of the ingestion. Testing that would have helped a lot. it would have been a 5 star rating if these things had gotten any attention

Really good introduction to the concepts of CQRS and Event Sourcing in a practical way. One thing I feel is missing is more content regarding a full scale production system (what happens with the event store as it grows over time, caveats of replaying the entire read db when you have other systems that react to replayed events, etc) -> Keep in mind though that this issues are discussed in the questions and Sean gives really clear answers!