Best way to have an application run

I have a daily CSV file dumped to my filesystem, and I need to parse each row of it appropriately into an XML document of a certain format. From there, I need to send one POST request with that XML for each row as the body until all of the rows are sent.

It occurred to me that there's a few ways this can be done,

– a person can invoke the tool at the time of day the CSV file is available

– If the time of day is fixed, I can have some sort of mechanism invoke the tool automatically (e.g. cron job, etc?)

– i could have a long standing application poll for the file and act once it's found

– maybe an Observable pattern, but I don't know how the Observer could be notified without effectively polling for the file. And this doesn't seem like a genuine use-case for the pattern because there would only be one Observer.

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My first instinct was I'll write a Node app. But I'm struggling to even see the justification for anything other than a Cron job right now. I know there's a better / more sophisticated way to do this. Any suggestions would be helpful.

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