Tech was only about 10 percent of the workforce, but it had an outsized impact. The city was turning over. People kept coming. The Mission was plastered with flyers addressing newcomers. Nobody cares about your tech job, the flyers read. Be courteous of others when in public and keep the feral careerism of your collegial banter on mute.

Rents rose. Cafés went cashless. The roads were choked with ride-shares. Taquerias shuttered and reopened as upscale, organic taco shops. Tenement buildings burned, and were replaced with empty condominiums.

On the side of San Francisco where streets were named after union organizers and Mexican anti-imperialists, speculators snapped up vinyl-sided starter homes and flipped them. Amid tidy rows of pastel Edwardians, the flipped houses looked like dead teeth, muted and ominous in freshly painted, staid shades of gray. Newly flush twentysomethings became meek, baby-faced landlords, apologetically invoking arcane housing law to evict inherited long-term tenants and clear the way for condo conversions. Real estate developers planned blocks of micro-apartments, insistent that they weren’t just weekend crash pads, but the new frontier of millennial living: start small, scale up later.

Against the former factories and chipping Victorians, the car-repair shops and leather bars, downtown’s new developments looked placeless, adrift. To differentiate themselves, they added electronic locks and Wi-Fi-enabled refrigerators, and called the apartments smart. They offered bocce courts, climbing walls, pools, cooking classes, concierge services. Some hosted ski trips to Tahoe and weekend trips to wine country. They boasted bicycle lockers, woodworking shops, dog-wash stations, electric-car chargers. Half had tech rooms and coworking lounges: business centers designed to look like the residents’ offices, which were themselves designed to look like home.