When you say the PostingService ‘injects’ the other services mentioned, do you mean your PostingService has other services injected into it? For example, the service struct likely looks something like the example below where the property types are interfaces (I’ve just made those names up of course):

type PostingService struct {
    RepliesSvc repliesCreator
    ThreadsSvc threadsSetter
    FiltersSvc filtersGetter
    LogsSvc    logger
}