Not sure if that was an intentional mistype of "sweat spot", but given your description of their competence level I read that as a word play on sweating due to

Not sure if that was an intentional mistype of "sweat spot", but given your description of their competence level I read that as a word play on sweating due to the nervousness of their code being ready to blow up vs. "sweet spot" meaning the good balance between cost and value. Very clever :)