Trunk-Based Development

Trunk-Based Development (TBD) is a workflow where all developers integrate to a single shared branch (the "trunk" or main) very frequently — at least once per day. Feature branches exist but are short-lived, merged within hours to days. Used by Google, Meta, and Netflix.

01.Core Principles of TBD

Integrate to trunk at least once a day. Feature branches live less than 2 days — long-lived branches accumulate conflict debt. Comprehensive automated test suite is non-negotiable — trunk must be deployable at every commit. Feature flags hide incomplete work in production. Small, focused commits over large batched ones. Code review happens fast because PRs are small.

Branch Visualization

main

feature

HEAD

02.Feature Flags Enable TBD at Scale

Feature flags (feature toggles) let you merge incomplete code to trunk while keeping it invisible to users. The code is deployed but wrapped: if (flags.newDashboard) { /* new code */ }. This completely separates deployment (when code ships) from release (when users see it). Teams can merge daily even for multi-month features. Flags are managed via config, no code change needed to flip them.

Commit Timeline

a1b2c3d

init

b2c3d4e

feat

c3d4e5f

fix

d4e5f6a

HEAD

Commands

commands — click to reveal output

git checkout -b feat/x

Short-lived branch — target merge within 1-2 days

git pull --rebase origin main

Sync with trunk multiple times per day

git push origin feat/x

Push for PR review (fast — small changes = fast review)

# PR reviewed and merged same day

Speed is the goal — small PRs enable this

git checkout main && git pull

Start next task from latest trunk immediately

git branch -d feat/x

Delete feature branch immediately after merge

KNOWLEDGE CHECK

What is the defining characteristic of Trunk-Based Development?

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