Subscriber lifecycle, service activation, and order-to-activate orchestration.
3 questions in Telecom.
A port is an externally timed event you do not control, so your cease has to land with it and not before. The failures are asymmetric: cease early and the customer loses service, cease late and you keep billing a number you no longer serve while usage records still arrive.
An activation half-succeeded and nobody owns the divergence. Detect it by reconciling the network's view against the subscription record, classify which side is wrong, re-drive fulfilment from stored intent rather than patching either side, and treat the unbilled period as a decided commercial policy.
The order is decomposed against the product catalogue into technical tasks on separate systems, each with its own latency and failure mode. Because nothing spans them transactionally, correctness comes from idempotent tasks, compensating actions, a fallout queue and jeopardy monitoring.