Let's say you have a 15-year-old e-commerce site and you need to modernize it. You've probably heard of something like SOA or microservices and want to implement them. But you have no idea how to move from a monolith to SOA while maintaining live production the whole time.

In this talk, we'll walk you through how we approached this, what's the first step? How we leveraged the Strangler Fig Pattern (presented in Shawna Spoor's talk) with Symfony to set up our migration path. How to manage such an architecture on a daily basis? How do manage source code? How do we handle users's session between legacy and new apps? How do we benefit from Symfony's Container in the legacy part? How to hunt for bugs thanks to OpenTelemetry?

This talk will give you some tips from our experience.