Previously, previously, previously, previously, previously.
Wait, so Fourier transforms basically work like epicycles?
FFS, I might have just understood them better than I ever did at university.
Yea, I wish my textbooks had contained an animation like that. You'll like 3Blue1Brown's explanation:
1) Vectorize drawing using polar coordinates
2) Convert time-domain series to frequency-domain series using Fourier transmorm
Well, 3a: blockchain storing them, ofc