Question: The messaging app that is an acronym for "Searchable Log of All Conversation and Knowledge" was founded by a business of what descent?
Sentence (from "Stewart Butterfield"): Daniel Stewart Butterfield (born Dharma Jeremy Butterfield, 1973) is a Canadian entrepreneur and businessman of Polish descent, best known for being a co-founder of the photo sharing website Flickr and team messaging application Slack.
Relevant evidence: Yes