Currently for the MVP we are not doing anything fancy, the 'hot' list is ordered (desc) by number of upvotes and 'trending' is nearly the same as 'latest' except limited to last 7 days. We will keep monitoring and keep either 'hot' or 'trending' in the future. We want to keep the ranking of each product simple and based on what people are upvoting, so there won't be any hidden scoring.