Internally I've long switched to UUIDs instead of auto increment columns for my Doctrine entities. But as soon as I'm in the realm of business logic or serialization, I always convert the UUIDs to strings. Which doesn't really makes sense as I loose a layer of type safety through that.
Luckily I stumbled over the
uuid-normalizer package which extends the Symfony serializer and adds to option to serialize UUIDs from Ramsey Uuid. Now I'm able to use UUIDs everywhere.