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Not sure what being a programmer has to do with a cover. It's a keyboard cover, they aren't for professions.

There are many popular brands, and cheap ones on Amazon and the like. Search "macbook keyboard cover" or something to that effect. Maybe work in what model you actually have into your search.
 
Wash your hands and don't use a keyboard cover. All other covers I've tried impeded typing speed in one way or another.
 
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