Because trading systems can malfunction, what checks should be confirmed to make sure that everything is in working order? Also because speed is important, should checks be done before/after sending orders?
How do you trade differently based on the size of your positions? What systems should be known in order to know what our position is before every order we send?
What if a counterparty comes to you and says that they know a trade against you that you do not recognize? What systems should be verified and what could have gone wrong?