Two topics are covered. First, in small teams, a developer should take care of more than just development. Like onboarding emails, error handling, micro-interactions, meaningful empty states, error states, scaling, and server costs.
Second: tools, low-code solutions, and third-party services to build MVPs faster. CRM, customer support, hosted authentication, billing, logging, error reporting, analytics, status page, etc. Mostly in the React and JS world.