Schedule

Structuring an application around its domain rather than its framework is an old idea. Making it practical has sometimes felt like swimming against the current.

Thanks to the way Symfony 8 leverages modern PHP, this drastically changes. Recent evolutions in both the language and the framework align naturally with hexagonal thinking and tactical DDD patterns — no workarounds, no fighting the tools.

Join me as I wear both my Core Team member and DDD practitioner hats to give a pragmatic look at putting your business logic first, building applications that scale with your domain's complexity and remain maintainable as they grow, with Symfony's blessing.

When inheriting an unmaintained legacy Symfony application, the real question is not “how to migrate”, but rather “where to start without breaking everything”.

In this talk, I share an honest retrospective of a Symfony migration carried out in production, on an aging application with limited documentation, few tests, and dependencies on components that are now obsolete.

Through this journey, I offer a reading of the battlefield: risk areas, false good ideas, and decisions that seem obvious on paper… but turn out to be dangerous once confronted with real-world constraints.

In particular, we will cover:
- How to step back from an unmaintained legacy codebase and identify the real problems
- The false good ideas we encountered during Symfony legacy migrations
- Common mistakes observed in the field, and how to avoid or mitigate them
- Small levers that make a big difference (order of actions, scope, tools, trade-offs)
- Key lessons learned from this migration: what we would do again, and what we would clearly avoid

This talk is aimed at developers working with inherited Symfony applications, often business-critical, who must move forward with limited visibility and very little room for error.

The goal is not to promote a perfect or universal method, but to share a real, lived experience, and provide attendees with concrete reference points, clarity, and practical tips they can apply to their own migrations.

Developing a Symfony application is fun. But manual tests can become tedious. So can debugging.
And it might also be too early in the design process to start writing tests.
But we can go in between: write new console commands.

With the latest Symfony Console updates, writing interactive commands has never been easier.
When used to test your code and your API design, they become a perfect debugging tool — for you, and for the developers who will later use your code.