Don't Panic — Trunk-Based Development

Trunk-based development is a way of arranging software work around one shared branch, usually called main. The point is not to admire the branch name as though it had won a small trophy. The point is to make each change join the current shared product state while it is still small enough to understand, test, and repair.

The old trouble is delayed integration. Two changes can look perfectly polite on their separate branches, then meet weeks later and discover that they disagree about reality. A small batch keeps that meeting short. The next change starts from the newly integrated trunk, so the team learns from the same result instead of maintaining several private versions of the product.

This does not require a heroic leap directly onto main. A small team may commit there after local checks. A team that needs review can use a short-lived branch, run checks, get review, merge promptly, and delete it. Waiting counts. A five-minute pipeline does not make a four-day review queue less of an integration delay; it merely gives the delay a helpful progress bar.

Large work also has an escape hatch that is less dramatic than keeping it away from everyone for a month. A feature flag can let code integrate while its user-facing behavior remains hidden. A branch by abstraction can let old and new implementations coexist behind an interface while callers move in steps. Both are temporary structures. They need tests, ownership, and removal, or the trunk becomes a museum of cautious decisions.

The surprising part is that a green trunk is not a certificate of perfection. It is usable evidence: the shared baseline passed the checks the team relies on. When it breaks, restore it before adding unrelated changes. When a release branch exists, use it to maintain a supported release, not as a second ordinary development line. One mainline is a coordination choice, not a ban on every other branch.

Read the Intro for the full model and the supporting techniques. Use Slides for the flow and decision points. Keep the Cheatsheet nearby when shaping a change, diagnosing a queue, or deciding whether a temporary control has earned its removal. Then take the exercise: it turns the idea into a small local Git history, which is considerably less alarming than discovering it during a large merge.

Don't Panic — Trunk-Based Development

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