It is recommended that functions are stateless and idempotent where ever possible. Associate any required state information with your data. For example, an order that is being processed will likely have an associated state member. A function could process an order based on that state while the function itself remains stateless.
and very importantly it is recommended that idempotent functions have timer triggers. For example, if you have something that absolutely must run once a day, we should write it so that it can run at any time during the day with the same results. The function can skip when there is no work for a particular day. Also, if a previous run failed to complete, then the next run should pick ...
