Neither - Nor
You can specify on the NEXT level what you want. If if does not lead to an efficient implementation it will not work. At least, if you oversee some critical effect because you have a unexperienced team, after silicon out.
So get familiar what work at bottom, or the NEXT lower level, unless you start at the NEXT higher level.
Working in levels is present every time and is some kind of work efficiency gain. The links between the levels is the critical KnowHow. In both directions: BottomUp and TopDown.
I did not share the view of topdown designers defining e.g. blocking specs which require years of search give entry to a mine field of patents to do it efficient in silicon.
Or look at the peoples which say everything should go digital: Blame
They could not tell you if the channel filtering is digital what are the +sample rate and +number of bits for the ADC, do not think of the ADC power and so on.
They tell you that "buzzword" w/o the background what a shame.