ROLL WITH IT | Butterfield in Slack’s Vancouver office; the custom seating was designed by Leckie Studio and Slack’s head of design, Brandon Velestuk.

THE OFFICES OF SLACK, in the tech-centric SoMa district of San Francisco, feature endless swaths of bare wall-to-wall carpet awaiting the installation of desks and chairs. Wires hang loosely from ceilings, eager to attach themselves to future computer workstations. Blank whiteboards idle at the edges of soon-to-be-bustling rooms. These are anticipatory spaces—the headquarters of a company poised to explode with new hires.

Photo strips taken of guests at Slack’s one-year-anniversary party, held in February in San Francisco.