As individuals we work in transient isolation to reduce the impact of work in progress on each other. Organizations isolate WIP by using only official versions of 3pty sources and by producing official releases for customers.
Multi-stage continuous integration (MSCI) scales CI to large distributed environments by isolating work in progress at the team level. Changes move from individual to team to mainline as fast as CI allows, but stop on failure.
MSCI is particularly important in a distributed environment where fixes to problems exposed by CI can be delayed by a full day.