AFUP Day 2025 in Lille: Talks and Lessons

On Friday, May 16, 2025, Lille hosted the 7th edition of AFUP Day. This must-attend event for the PHP community brought together developers, experts and enthusiasts in the warm, intimate setting of the La Comédie theater. Organized by the AFUP Hauts-de-France chapter, it was a chance to review web development best practices while encouraging exchanges between professionals. As a reminder, we already covered AFUP Day 2024 (in French), which was also held at the same theater in Lille.

Over the years, AFUP Day has become more than a series of talks: it is a special moment to share experiences, learn about the latest technological changes and meet your peers in a friendly setting. With its spacious stage and rows of velvet seats, the La Comédie theater was a particularly pleasant venue for this day of sharing. From the welcome desk on, the mood was warm: pastries, coffee and smiles accompanied the reunions between regulars and the discovery of new faces.

A rich program around PHP, Symfony and the modern web

The 2025 edition offered a rich program that mixed technical depth, lessons learned and perspectives on career growth. In the opening keynote, the AFUP Hauts-de-France team reminded everyone how important these meetups are for keeping the community alive and strengthening ties between developers in the region. The volunteers, recognizable by their t-shirts, kept the organization running smoothly all day, watching over each session and guiding attendees between the different areas.

The common thread of this edition was clear: how to get the most out of PHP and its ecosystem in 2025, whether in terms of performance, software architecture or career growth. To find out which other events to follow in the Symfony and PHP world (in French), our conference guide lists the must-attend gatherings. Each talk brought concrete insight rooted in field experience.

PHP and Symfony talks: performance, architecture and real-world lessons

Clément Talleu kicked things off by explaining how to improve the user experience with anticipatory caching. Instead of waiting for the user's request to generate a response, the idea is to precompute and store the data that is likely to be requested. A well-applied strategy makes interfaces more responsive by adapting to user journeys. Through practical cases from Symfony projects, he showed the direct impact of this approach on the fluidity of web applications, with response time gains that were sometimes spectacular. The room paid close attention to the before and after metrics he presented, which made the benefit tangible and immediately applicable.

Nicolas Fatrez then took over with one of the most memorable talks of the day. He shared the story of a company whose information system had been frozen for a decade: a PHP 5 monolith with no tests, no versioning, deployed manually over FTP. With humor and self-deprecation, he detailed the gradual modernization: moving to PHP 8, setting up Docker, introducing GitLab CI, and the challenges of developers facing obsolete infrastructure. His story drew plenty of laughs of recognition from the audience, because many developers have run into this kind of situation. Beyond the anecdote, he offered a pragmatic methodology for tackling these migrations without breaking everything, by prioritizing the work and getting the teams on board.

Mathieu Desnouveaux took us into the banking world with a talk on multi-source pagination for tracking transfers. He detailed the challenges of handling data flows from multiple sources (third-party APIs, internal databases, flat files) and the solutions used to guarantee optimal performance. He illustrated especially well how complex pagination becomes when the data does not come from a single SQL table but from heterogeneous sources. He presented the sorting, merging and caching strategies adopted to deliver a smooth user experience despite the many data origins.

Nathan Pretot described the transformation of a RAD application into a clean architecture. Starting from a project built quickly with Symfony's RAD tools, he showed step by step how to restructure the code to separate responsibilities, isolate the business domain and make the application testable. He highlighted the gains in maintainability and scalability, and shared the pitfalls to avoid in this kind of redesign, in particular the risk of over-engineering and the importance of migrating gradually (in French) rather than rewriting everything at once.

Symfony UX, multi-tenancy, PHP performance: lessons and career growth

Pierre Marichez told the story of how he went from developer to CTO without ever leaving the technical side. Drawing on his experience, he gave concrete advice for taking on management responsibilities while staying grounded in code. His presentation resonated with many senior developers who wonder about career growth without wanting to give up what they love. He stressed the importance of delegating wisely, splitting your time between management and technical work, and continuing to contribute code on high-value topics.

Amélie Guers focused on integrating Symfony UX into a Sylius e-commerce project. She showed how to enrich frontend features simply and effectively, without weighing down the technical stack. Symfony UX components such as Live Components and Turbo make it possible to build dynamic interfaces with a minimum of JavaScript, which makes maintenance easier for PHP teams. Her live demo, with an interactive shopping cart built in a few lines, convinced the audience that these tools are mature.

Mehdi Zaidi covered how to implement a multi-tenant architecture using Symfony, API Platform and PostgreSQL. He presented practical solutions for adapting existing projects to this model and explored the different data isolation strategies (schema per tenant, database per tenant, column discrimination). He laid out the pros and cons of each approach clearly, backed by production feedback.

Baptiste Leduc closed the talks with a session on lazy loading, exploring its uses beyond the ORM layer. He showed how this technique can optimize other parts of PHP applications: loading configuration files, instantiating expensive services or resolving dependencies. Building on Symfony's ghost objects and value holders, he opened up perspectives that many developers had not considered.

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Rich exchanges and valuable encounters

One of the major strengths of AFUP Day Lille is its human side. Between talks, the coffee breaks and lunch were great moments to chat informally with the speakers and other attendees. The catering area, set up in the theater's foyer, naturally encouraged conversations in small groups.

These discussions made it possible to compare experiences, talk about common problems and discover new approaches. In a world where remote work has become widespread, these in-person meetings are now essential to keep the connection alive and spark collective intelligence. Several attendees noted that the informal exchanges gave them as much as the talks themselves, unblocking problems they had been stuck on for weeks. These events also remind us how important open source contributions (in French) are, because the PHP ecosystem celebrated that day relies largely on the volunteer commitment of its community.

A successful edition

This 2025 edition will be remembered as a success on every level. Everyone praised the diversity of the topics, the quality of the talks and the richness of the exchanges. The single-track format, which lets all attendees follow the same talks, strengthens the sense of belonging to a community united around a language and an ecosystem that keep evolving.

The Efficience IT team, a Symfony agency in Lille (in French), was delighted to be among the sponsors of this event once again this year. Supporting AFUP Day Lille is a no-brainer: it is a chance to meet the community, talk about PHP best practices and showcase local expertise. See you next year for a new edition that already promises to be great.