Colin Marshall stands around Hackney, London's "Tech City" with urban designer Euan Mills. They discuss how to tip in a London bar and how to cross a London street; when he realized he has become an urban designer, and what that entails; the hugeness and non-understandability of the spread-out, car-dependent, crime-fearing São Paulo, where he grew up hating cities; the development of his interest in people, not buildings, and cities as networks of people; how he came to London, a city of paradoxes that still gives him the sense that anything exciting that happens will happen there; what, exactly, makes a "high street"; how zoning differences between the U.S. and the U.K. affect neighborhoods, and the sorts of changes he's seen in London's in the 21st century; This Isn't F***ing Dalston, and what it told him about the edges of neighborhoods; how long a place takes to gentrify, and how it then matures, coming to embody all its eras at once; what bars, and the price of a pint of Guinness, tell you about a neighborhood; how everybody likes "authenticity" and nobody likes to feel like a target market; the test of a business you feel uncomfortable entering; what it means then the charity shops, 99p stores, and betting offices start showing up; the change in places like the growth in our hair, so show we don't notice it; the necessity of combining local experience with placemaking expertise; São Paulo as a repeat of  London in the 1960s, and the bad reputation top-down planning developed in that era; what to look for in London, like the intentions of a place or its people; the importance of thinking about who owns the land; and what effect the London weather might have on all this.