Write down what your system does when the broker says nothing

Not an error. Not a rejection. You send an order and receive silence. This is the state most retail setups handle worst, because it's ambiguous by construction: the order may have arrived and be working, may have arrived and filled, or may never have arrived at all. Your software cannot tell the difference from where it's standing. The wrong response is to resend, which is how one intended position becomes two. What I do now: on timeout, stop sending. Query the broker for open orders and recent fills. Reconcile before any further action. If the query itself fails, alert and do nothing — doing nothing is a valid state and it is much better than guessing. The general rule I took from this: when you don't know, find out; never assume the more convenient of two possibilities.