Like a well-built home, great software focuses on giving its users hundreds of small, satisfying interactions. A great transition in a mobile app gives us the same feeling we get from using a well-made door handle on a solid oak door — you may not be able to put your finger on it, but man, does the house ever feel well built. Slack is really fun to use. It feels like a well-built house.
Andrew Wilkinson lays out the design work they did for Slack and how it is (or might be?) their secret recipe for success.