Open APIs

You are right, that you cannot prevent a race condition. What I think is being overlooked in the responses are these parts of Jonathan's example: ... don't challenge realism of the specific example - it's the principle that's important. ... ...

I think the answer is, "a bit of both". While there are a number of strategies to prevent the most egregious occurrences of this issue, the fact that even these activities (locking/etc) take some amount of time means that you can never truly prevent ...

How much of this scenario just boils down to state management? If I apply the HATEOAS (Hypermedia As The Engine of Application State approach) concept I would say the response to the GET on the resource should convey, via hypermedia controls/link object, ...

In this case the "root cause" is the separation of Party information from that of Bill Calculation in two separate applications with a standard TMF API between them. So the "root cause" is the fundamental non-monolithic application design, which is ...

While I agree, that keeping things simple is preferable, the experience is that many large Telcos are not satisfied with that and will not accept solutions that do not consider the questions that Jonathan is asking. The problems are real. You won't ...