Cool! But how did you get the initial dataset of 643,000+ Shopify stores (data as per your “About” page) in the first place, to then scrape the products from their /products.json feeds? Or did you just try a huge list of domain names at random?
Bought an initial list of 2m stores for a few hundred dollars from a website called "Built With". Think they are used for building sales outreach lists. Then narrowed down the focus to stores to US only and between $100k - $1m in revenue to keep the initial data set manageable (and the CPU / Storage costs reasonable).
Does "Built With" provide that data? How accurate do you think it might be?