Table of contents

• Defining team roles and access levels
• Using CODEOWNERS to manage review responsibility
• Configuring branch protection for safe collaboration
• Enforcing merge workflows in a monorepo
• How Graphite improves PR workflows in monorepos
• Summary and recommendations

Defining team roles and access levels

Monorepos host multiple projects in one repo. On GitHub, repository roles (Read, Triage, Write, Maintain, Admin) help enforce access control:

Best practice: apply least privilege. Give teams only what they need.

Using CODEOWNERS to manage review responsibility

GitHub’s CODEOWNERS file allows per-directory or file ownership. When a pull request modifies owned files, GitHub auto-requests reviews.

Example:

*                    @my-org/monorepo-maintainers
/apps/               @my-org/frontend-team
/services/           @my-org/backend-team
/.github/workflows/  @my-org/devops-team

Best practices:

• Use GitHub teams (@org/team) instead of individuals.
• Ensure listed owners have Write access.
• Require code owner reviews via branch protection rules.
• Document expectations in CONTRIBUTING.md.

CODEOWNERS provides transparency and scalable review ownership in shared codebases.

Configuring branch protection for safe collaboration

To enforce process and quality gates, enable GitHub’s branch protection rules on main (and other key branches):

Recommended settings:

• Require PRs before merging.
• Require at least one or two approvals.
• Require review from code owners.
• Require status checks to pass (e.g., CI, tests).
• Enforce linear history (optional).
• Optionally use merge queues or auto-merge.

Advanced:

• Protect release branches with stricter rules.
• Restrict pushes/merges to automation bots.
• Use rulesets to apply standards across multiple branches.

These controls make sure changes are reviewed and verified before entering critical branches.

Enforcing merge workflows in a monorepo

Combine CODEOWNERS and branch protection to enforce a consistent process:

• All changes go through pull requests.
• Every PR must have owner and peer approvals.
• CI must pass.
• Use squash or merge commits consistently.
• Avoid bypassing protections—even for admins.

Large monorepos benefit from clearly documented workflows, including guidelines on PR size, commit hygiene, and reviewer expectations.

How Graphite improves PR workflows in monorepos

Graphite builds on GitHub to improve change management, especially in large, fast-moving monorepos.

Key benefits:

• Stacked pull requests: Break large changes into small, reviewable chunks. Each PR builds on the previous. Graphite manages the stack and handles rebases automatically.
• Faster iteration: Developers don't wait for one PR to merge before working on the next. Reviewers can start at the bottom of the stack.
• Automated reviewer assignment: Graphite Automations assigns reviewers based on file paths, types, or custom logic—more flexible than static CODEOWNERS.
• PR dashboard: Centralized view of pending reviews and stacks, helping reviewers and authors stay organized.
• Merge queue: Safely serializes PRs with rebase and CI enforcement. Graphite respects stacked PRs’ order, ensuring safe merges.

Compared to GitHub alone, Graphite brings better visibility, review efficiency, and control—critical in high-scale environments.

Summary and recommendations

To manage access and reviews in a monorepo:

1. Set team roles with the least privilege necessary.
2. Use CODEOWNERS to define review responsibility by directory or file.
3. Protect branches with required PRs, code owner reviews, and CI checks.
4. Document review and merge processes clearly.
5. Adopt Graphite to handle stacked PRs, automate reviewer assignment, and streamline merges.

With GitHub as the foundation and Graphite as a workflow enhancer, teams can scale confidently in monorepos without sacrificing quality or velocity.