I found it very hard to find to find the domain problems of E-Commerce as someone who has 0 domain experience.
needgap addresses this - https://needgap.com/problems?q=ecommerce . One can search for problems in a particular domain by using search or the category hashtag.
I'm also considering individual hashtag based subscription, Say like subscribing to just eCommerce based problems and whenever a problem for eCommerce is posted you'll receive the email notification. Would you be interested in such a feature for monthly USD 5?
Here is a list of industries (domains) published by BLS https://www.bls.gov/iag/tgs/iag_index_alpha.htm
Off-topic, Thanks for this list of domains it might come handy to solve the problem of website categorization - /problems/355 .