Short reflection
On 20th January I had the chance to run a workshop during SymfonyOnline 2026, titled refactoring towards Clean Architecture.
What made this session special for me was the fact that it was my very first remote workshop ever.
Going into it, I honestly expected around 10–15 participants. Instead, almost 25 people showed up, which was both surprising and incredibly motivating. Even more important than the number was the level of engagement — lots of thoughtful questions, real-life problems, and open discussions around legacy code, boundaries, and architectural trade-offs.
Running a remote workshop is very different from speaking on stage. You don’t see the whole room, you don’t feel the same energy — or at least that’s what I was afraid of. In reality, the interaction, questions, and feedback made it feel very alive and dynamic.
Of course, it wasn’t perfect. There are a few things I already know I want to improve next time — pacing, timing of exercises, and some technical details. But overall, for a first remote workshop, it went surprisingly well, and I’m genuinely proud of how it turned out.
Thank you 🙌
I want to say a huge thank you to everyone who joined the workshop.
Your questions, openness, and willingness to discuss real-world problems made this session truly valuable and enjoyable for me as a trainer.
Big thanks as well to the SymfonyOnline team for the trust and the opportunity to run this workshop.
It was a great experience — and definitely not the last one.
Questions & Answers from the workshop
During the workshop, a lot of great questions were asked.
Below you’ll find all of them collected in one place, together with my answers, so you can come back to them anytime. Bear in mind that these are just my suggestions. As I said in the workshop 👉 in the software architecture, everything is a trade-off, so keep that in mind!
I think it’s not a realistic starting point. You’re refactoring from an already well set up project. Most of the application out there are not so well structured from the start. What if you’re dealing with a messy monolith? Do you first refactor to remove front-end code (templating, symfony-ux, …) to be in the same case and then refactor to clean architecture?
In the APP that we were working on, the UI was JSON, as it was an API. But, you can apply same principles to project that is a regular HTML. The problem will be with testing – you will need to the through the UI, to have the safety net. Your primary adapter will be the place where the HTML code will be produced.
It seems we’ve focussed on covering comment creation with ‘functional’ tests. Is this the recommendation when refactoring versus at the unit/molecular level, i suppose those kinds of tests are less resilient to the changes we’ll be making?
It is recommended to write a functional test, as this works as a safety net for refactoring. Later, with introduction of proper layering, you can keep one functional test as happy path, and test the layers via unit tests.
Do you usually add more assertions to this test, like:
self::assertSame(‘Nice article.’, $payload[‘comment’][‘body’]);
It is up to you how do you write assertions, as long as they cover the code and they are proper safety net.
Longer term do you recommend bringing fixture/entity creation closer to the tests? Currently the tests are expected to somehow know a fixture exists with the reference ‘test-article-user-first’?
Fixtures are nice for start, but in more complex project they become a problem, therefore I can recommend a builder pattern. This allow to have flexibility like ArticleBuilder::new()->withSlug(‘test’)->build()
Have you ever had problem with this new structure when upgrading projects (recipes, …) ?
Not yet, but I think that depends on the recipes.
Do you keep existing tests as is or do you restructure them also to map the new code structure ? For exemple with a new “testClean ” namespace also
In one medium size project we did testsClean, to have new tests on the side. It is optional.
Why have we introduced comments repository interface here; can’t we directly use DoctrineCommentsRepository?
This way you would break The Dependency Rule, you read more about it in the Uncle Bob article: https://blog.cleancoder.com/uncle-bob/2012/08/13/the-clean-architecture.html
Can a UseCase use another UseCase? or it’s a no-no?
Of course, you can create a composite UseCase that will use other use cases 😀
Where should we log, in which layer?
For logging I can recommend using the PSR interface – and treat it as shared component – it can be used on any layer where needed.
Going back to the conversation we were just having on use cases, comment entities etc.
Is the relationship between a controller and a use case, is it 1:1?
Could a controller leverage multiple use cases, for example, the comment controller depends on FindArticleBySlugCase and a CreateArticleCommentUseCase? Is this bad practice?
I can recommend discussing this with peers, either use multiple use cases in the controller, or create a composite use case for that purpose 😀
Can you please briefly summarize one more time what we did in the last step with CreateCommentHttpController? So, why we did it?
This is the introduction of the Primary Port and Primary Adapter. The Primary Port is an interface extracted from the Use Case. The Primary Adapter is the HTTP controller, which adapts the HTTP Request/Response to the Use Case needs. This taken from the Ports & Adapters aka Hexagonal architecture. You can read more here: https://herbertograca.com/2017/09/14/ports-adapters-architecture/#more-8817
How broad/narrow should the functionality of a use case be defined? e.g. CreateArticleComment vs ManageArticleComments (i.e. might include other comment ops, not just creation).
It should comply with the S from SOLID – Single Responsibility Principle, or Single Reason to Change. Consequently I can recommend sticking with option A.
Is there a need (or example) for multiple different implementations of a primary use case? They rely on secondary port interfaces, does that give us the flexibility we need?
There will be only one implementation in the production code, always, there could a fake/mock/stub in the tests as well. The whole point of the introduction of that interface, is to have an abstraction over the Use Case/Application layer, so we can leverage The Dependency Rule, you can read more about it here: https://blog.cleancoder.com/uncle-bob/2012/08/13/the-clean-architecture.html
So, Hexagonal architecture is clean architecture applied to each identified bounded context of an app?
No, Clean Architecture borrowed the ideas from the Hexagonal architecture (the idea of ports and adapters).
flush() is called inside the save/delete methods of the secondary adapter implementations.
Do you do that the same way in complex projects?
In my view, this breaks the Unit of Work pattern, because flush() implicitly commits all changes accumulated in the EntityManager, not just the current entity. This can lead to unintended side effects, trigger persistence-related behavior at unexpected moments, and reduce control over transaction boundaries at the use-case level. As a result, transactions have to be introduced manually where Unit of Work could otherwise handle them naturally, leading both to extra implicit commits and additional explicit transaction management.
Yes, in the project that we were working on it was not a problem, but in more complex it could. There are many possible solutions to that, via event listener, via middleware, etc.
How should events and event listeners that are highly coupled with framework (Doctrine event listeners for example) be handled? In which layer should they be? Should they be somehow decoupled from framework?
They are already coupled to Doctrine, so keep that in the Framework layer 😊 We went over it at the end of the workshop.
Do you keep only entities in the Domain layer, or do you also include domain services? In which cases do you consider it appropriate to place a service in the Domain layer?
If you need domain service, go for it. As I said, we didn’t dive deep into DDD here, we would need one more day 😅
Additional materials
For those who would like to go deeper, here are some extra materials I personally recommend:
🗂️ Slides 👉 https://speakerdeck.com/ddziaduch/refactoring-towards-clean-architecture-workshop-symfony-online-2026
💻 Repository & workshop branch
This is the repository we worked on during the workshop, including the exact branch used in the exercises:
👉 Repository: https://github.com/ddziaduch/refactoring-towards-clean-arch-workshop
👉 Workshop branch: sf-online-2026
📚 Books
- Clean Architecture (theory) – by Robert C Martin aka Uncle Bob – nice to read
- Get Your Hands Dirty On Clean Architecture (practice) – my and my team learned most from it – I can highly recommend it
- Fundamentals of Software Architecture (more than just clean architecture) – I finished this lear year, and it shows more than just Clean Architecture, very good read as well
My talk about Framework Agnostic – a presentation about Clean/Hexagonal architecture.
The Software Architecture Chronicles – a series of post by Herberto Graca about the evolution of the architecture.
The Deptrac tool – the static analysis tool I showed
Final thoughts
Once again, thank you for taking part in the workshop and for the great atmosphere.
I hope the ideas and tools we covered will be useful in your day-to-day work.
Best of luck applying them in your projects — and hopefully see you again at another conference or workshop 🙂
