Merge small. Merge often.
In trunk-based development everyone merges to one main branch at least daily. Unfinished features hide behind flags, not in branches.
Long-Lived Branches
Trunk-Based
Feature branches that live for weeks.
Branches that live a day or two at most.
One big, painful merge at the end.
Small merges, many times a day.
Unfinished work hidden in branches.
Unfinished work hidden behind feature flags.
Merge conflicts every release.
Conflicts caught while they're tiny.
Merge small. Merge often. Hide with flags.