Mendercon2022: From Chaos Code to Hexagonal Architecture

The talk will present the techniques to refactor legacy code in order to move to a clean architecture, that separate business logic from technical infrastructure.

Transcript

1. From Chaos Code to Hexagonal Architecture Oussama BADR / @ousamabadr CTO/Software Engineer @Agil-IT - Paris #mendercon2022
2. What we will discuss: • Introduction • Legacy all around • Other Legacy Staff to consider • Hexagonal to the rescue • Hexagonal in Action • TL;DR #mendercon2022
3. Legacy all around #mendercon2022
4. Legacy all around #mendercon2022
5. Legacy all around #mendercon2022 “Legacy Code is also a code with no boundaries, and especially when it comes to business logic.” Oussama BADR
6. Legacy all around #mendercon2022
7. Legacy all around #mendercon2022
8. Legacy all around #mendercon2022
9. Legacy all around #mendercon2022 Layer Based Architecture
10. Legacy all around #mendercon2022 Flow of Layer Based Architecture
11. Legacy all around #mendercon2022 Why layers Based Architecture promotes legacy code
12. Legacy all around #mendercon2022 The whole company is locked
13. Legacy all around #mendercon2022 The code base without clean may die after distressing all the team
14. Legacy all around #mendercon2022 People may fall in burn out and quit the team.
15. Other Legacy Stuff #mendercon2022 You need to sell you idea and convince others that Legacy code is really LEGACY
16. Other Legacy Stuff #mendercon2022
17. Hexagonal to the Rescue #mendercon2022
18. Who invented Hexagonal architecture ? #mendercon2022 Hexagonal to the Rescue
19. Who is the second ? #mendercon2022 Hexagonal to the Rescue Alistair Cockburn American computer scientist (Source Wikipedia) “Hexagonal architecture” Article (2005): https://alistair.cockburn.us/hexagonal-architecture/
20. First Motivations: #mendercon2022 Hexagonal to the Rescue • The system can’t neatly be tested. • Impossible to shift from a use case to another. • It becomes difficult or impossible to change technologie. We can also add: • Test suite can slow down very quickly. • Changing one business logic becomes a “new project” • Developer may quits if productivity decrease. • …etc
21. #mendercon2022 Hexagonal to the Rescue Overall Architecture:
22. #mendercon2022 Hexagonal to the Rescue Boundaries between in/out
23. #mendercon2022 Hexagonal to the Rescue But we use interfaces + Dependency Inversion
24. …TL;DR #mendercon2022 ©mommyPoppins And you always deserve better…
25. #mendercon2022 Link to slides will be available on @ousamabadr
26. Resources #mendercon2022 • “The Clean Architecture” By Uncle Bob: https://blog.cleancoder.com/uncle-bob/2012/08/13/the-clean-architecture.html • “Hexagonal architecture” Article : https://alistair.cockburn.us/hexagonal-architecture/ • GitHub: Domain-driven-hexagon https://github.com/Sairyss/domain-driven-hexagon • GitHub: Implementation of a Hexagonal Architecture: https://github.com/thombergs/buckpal