My old grumpy mentor from France Télécom was often joking about the failure of the SOA Java stack (and particularly the state of RPC and Service Buses).

I don't remember his argumentation, but now that microservices put back SOA in fashion, I would like to hear some feedbacks and opinions about it.

What's different now which makes SOA more relevant ? What was good about the old tooling ? There's some very good pieces of blog about SOA architectures out there, are they still relevant ?