PHP was long designed as a strictly stateless language: one request, one process, and then everything starts over.

FrankenPHP fundamentally changes this model by allowing long-running PHP workers to run directly within a Symfony application. Not to turn Symfony into a Node-style server, but to give it capabilities it has never had before.

In this talk, I introduce a new pattern: application sidekicks. These are specialized PHP workers, outside the HTTP lifecycle, that listen to their environment and reconfigure the application in real time; without polling, without approximate TTLs, and without redeployments.

Through concrete use cases (Redis Sentinel discovery, dynamic feature flags, etc.), we’ll see how to evolve an existing Symfony application while staying true to its principles.

The goal: to show that PHP can listen, react, and adapt in real time, without sacrificing its simplicity nor its traditional robustness.