A bit of update, turn out that mix has a functionality for tracking caller of a particular module via xref, it can be used to note which file that need to be changed, though it does require full recompilation of code from every invocation, like
mix xref callers LoadService.V2.Loads.JobPreassignedTransporterCompanyData
(..recompile whole application)
lib/load_service/v2/delivery_order_management/jobs.ex (runtime)
lib/load_service/v2/loads/api/delivery_order.ex (runtime)
lib/load_service/v2/oban/job.ex (runtime)
