Stewart Butterfield, the co-founder and CEO of Slack is on the cusp of 50, and on the brink of stepping down as chief executive of the extremely popular communications-for-teams software company he built. Slack has more than 18 million active daily users, and was acquired by Salesforce in 2020 for $27.7 billion. Butterfield exclusively takes host Christine Lagorio-Chafkin through his fascinating career of building games, startups, abandoning ideas, and running the fastest-growing enterprise tech company of its time.