Microservices are small, autonomous services that work together to perform specific functions. They are loosely coupled and have high cohesion. Each service should have a bounded context and explicit boundaries to define its responsibilities. Integration between microservices should avoid breaking changes, be technology agnostic, and simple for consumers by hiding internal implementation details. The shared database should be avoided for integration, and REST is recommended for request/response integration over synchronous/asynchronous messaging. Testing should focus on fast feedback through consumer-driven contracts instead of flaky end-to-end tests. The system design will likely reflect the organization's communication structure.

2. ervices?
What is Microservices?

3. Microservices are small,
autonomous services that work
together

5. Modelli
Modelling Microservices

6. What makes a good service?
Loose Coupling + High Cohesion

7. The Bounded Context
Specific responsibility enforced by explicit boundaries

9. grationIntegration

10. Avoid breaking changes
Technology Agnostics
Simple for Consumers
Hide internal implementation detail
Integration Technology - what are we looking for?

11. Avoid at all cost:
The Shared Database

12. Decide between:
Synchronous vs Asynchronous
Orchestration vs Choreography

13. Recommendations
Avoid database integration at all cost
Strongly consider REST for request/response integration
Prefer choreography over orchestration
Avoid breaking changes and the need to version

14. User Int
User Interface

15. API Composition

16. UI Fragment Composition

17. API Gateway - not like this

18. Backends for Frontends done properly

19. esting
Testing

20. Mike Cohn’s Test Pyramid

21. End-to-end tests are...
Flaky, brittle, and slow

22. Consumer-Driven tests to the rescue
No real tests against the real consumers, use consumer-driven contract (CDC)

23. Recommendations
Optimize for fast feedback
Avoid end-to-end tests when possible (use consumer-driven contracts)
Use consumer-driven contracts to provide conversation between teams
Understand the trade-off between putting more efforts into testing and detecting
issues faster in production

24. Topics not covered
Splitting the Monolith
Deployment
Monitoring
Security
...and many more

25. Any organization that designs a system will inevitably
produce a design whose structure is a copy of the
organization’s communication structure