rio-services.scala

trait ServiceA {
  def createA(a: EntityA): RIO[_]
}

trait ClientB {
  def getB(bId: EntityBID): RIO[_]
}

case class ServiceA(clientB: ClientB) extends ServiceA {
  override def createA(a: EntityA): RIO[_] = {
    for {
      entityB    <- clientB.getB(a.idOfB)
      processed  <- somePrivateBusinessLogic(entityB)
      result     <- someMoreBusinessLogic(processed)
      _          <- logger.info(s"Successfully processed entity ${a.id}")
    } yield result
  }
}