What is Trunk-Based Development?

Trunk-Based Development (TBD) is a Git approach where the whole team works around a single main branch (usually main or trunk), and changes land in it very frequently and in small batches.

In simpler terms: "One main branch, frequent commits, minimal long-lived branches."

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#The main idea of Trunk-Based Development

• there is one central branch - main / trunk
• developers either:
  • commit directly into it (with protections),
  • or use very short-lived feature branches (hours or 1-2 days)
• code is continuously integrated and tested

No week-long feature branches.

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#What the work looks like in practice

#Option 1: no feature branches at all

1. Pick up a task
2. Make a small change
3. Run the tests
4. Commit to main

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#Option 2: with short feature branches

1. Create a branch from main
2. Do a small part of the task
3. Open a PR
4. Merge into main the same day
5. Delete the branch

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#How production is kept from breaking

In Trunk-Based Development, teams almost always use:

• feature flags (feature toggles) - the code is in main but disabled
• strict CI
• automated tests
• a ban on large PRs

Code can be in main but unavailable to users.

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#How it differs from the Feature Branch Workflow

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#Advantages of Trunk-Based Development

• Very fast releases
• Fewer merge conflicts
• Continuous integration
• Great fit for CI/CD

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#Disadvantages

• Requires high discipline
• Needs good tests
• Risky without feature flags
• Harder for beginners

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#When Trunk-Based Development fits

• frequent releases (several times a day)
• CI/CD
• an actively evolving product
• an experienced team
• delivery speed matters

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#When it does not fit

• rare releases
• large features without flags
• weak tests
• an inexperienced team

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#Short answer for an interview

Trunk-Based Development is an approach where development happens around a single main branch, and changes are merged into it frequently and in small batches, which simplifies integration and speeds up releases.