Quentin Hardy of the NYT provides this exceptional account of life in the Mid-Market area of San Francisco, close to the Financial District and a few blocks from the offices of Twitter, and of Spotify, Zendesk and other startup companies. Moving just a few blocks from the tech startups offices can take you into a different world with dilapidated housing, drug dealers, and housing for homeless people. Expensive resaurants and markets rub shoulders with poorer shops.