Enterprise Git Strategy

This document outlines an enterprise-level Git strategy using a Single Trunk approach with the master/main branch as the primary development line. This strategy emphasizes:

• Continuous Integration: All changes are integrated frequently into the main branch
• Tag-based Deployments: Deployments are triggered by Git tags on the main branch
• Approval-based CD: Deployments require approval gates for production environments
• Branch-based Testing: Feature and release branches are used for testing before merging

• Purpose: Production-ready code
• Protection: Protected branch with required PR reviews
• Deployment: Only tagged commits are deployed
• Merge Strategy: Squash and merge or merge commits (consistent across team)

Naming: feature/JIRA-123-description
Example: feature/USER-456-user-authentication
Lifetime: Short-lived (1-2 weeks max)
Purpose: Individual feature development

Naming: release/v1.2.0
Example: release/v2.1.0
Lifetime: Until release is deployed and stable
Purpose: Release preparation and bug fixes

Naming: hotfix/v1.2.1-critical-bug
Example: hotfix/v2.1.1-security-patch
Lifetime: Very short-lived (hours to days)
Purpose: Critical production fixes

Trigger	Branch/Tag	Actions	Deployment
Pull Request	feature/*, release/*	Build, Test, Security Scan	None
Tag (Development)	v*-dev, v*-rc*	Full Pipeline	Development/Staging
Tag (Production)	v* (release tags)	Full Pipeline + Approval	Production

Complete lifecycle of developing a new feature from conception to production deployment.

Step 1: Create Feature Branch

# Sync with latest master
git checkout master
git pull origin master

# Create feature branch
git checkout -b feature/USER-456-user-authentication

Planning Phase:

• Ensure feature is well-defined with clear acceptance criteria
• Use consistent naming convention with ticket/story number
• Always branch from latest master to avoid integration conflicts
• Inform team about new feature branch to avoid duplicate work

Step 2: Development and Testing

# Make incremental changes
git add .
git commit -m "feat: add user authentication service"
git commit -m "feat: add password validation rules"
git commit -m "test: add unit tests for authentication service"

# Push feature branch
git push origin feature/USER-456-user-authentication

Development Best Practices:

• Make small, frequent commits with clear commit messages
• Run unit tests locally before each push
• Follow coding standards and run linters
• Update documentation as you develop
• Use conventional commit format (feat, fix, docs, etc.)

Step 3: Create Pull Request

PR Requirements Template:

## Summary
Brief description of what this PR does

## Changes Made
- List of specific changes
- New features added
- Bug fixes included

## Testing
- Unit test coverage: X%
- Integration tests: Pass/Fail
- Manual testing performed
- Performance impact assessment

## Breaking Changes
List any breaking changes

## Checklist
- [ ] Tests pass
- [ ] Documentation updated
- [ ] Code review completed
- [ ] Security review (if applicable)

Step 4: Code Review and Merge

# After approval, merge to master
git checkout master
git pull origin master
git merge --squash feature/USER-456-user-authentication
git commit -m "feat: Add user authentication module (USER-456)"
git push origin master

# Clean up feature branch
git branch -d feature/USER-456-user-authentication
git push origin --delete feature/USER-456-user-authentication

Review Process:

• Minimum 2 reviewers required (technical + domain expert)
• Reviews completed within 24-48 hours
• All reviewers must approve before merge
• Address all review comments before merging

End-to-end release process from planning to production deployment.

Step 1: Create Release Branch

# From master, create release branch
git checkout master
git pull origin master
git checkout -b release/v1.3.0
git push origin release/v1.3.0

Release Planning:

• Define release scope and included features
• Create release notes draft
• Schedule release timeline with all teams
• Feature freeze - no new features after branch creation

Step 2: Release Preparation

# Update version numbers and documentation
# Update CHANGELOG.md
git add .
git commit -m "Prepare release v1.3.0"
git push origin release/v1.3.0

Preparation Tasks:

• Update package.json, version files, and configuration
• Update CHANGELOG.md with all changes since last release
• Update API documentation and user guides
• Ensure database migration scripts are included
• Validate environment-specific configurations

Step 3: Release Testing

Comprehensive Testing Phase:

• Automated Testing: Full regression, integration, performance, security testing
• Manual Testing: User acceptance testing, exploratory testing, UI testing
• Environment Testing: Deploy to testing environment and validate procedures

Step 4: Tag and Deploy

# When ready for release
git checkout master
git pull origin master
git tag -a v1.3.0 -m "Release v1.3.0: User authentication and notifications"
git push origin v1.3.0

# This triggers the CD pipeline

Deployment Process:

• Pre-deployment checklist completed
• Use semantic versioning with comprehensive tag message
• Monitor application health during deployment
• Run smoke tests after deployment

Emergency hotfix process for critical production issues that cannot wait for next release.

Step 1: Identify Critical Issue

Severity Classification:

• Critical Complete system outage, data loss, security breach
• High Major feature broken, significant user impact
• Medium Minor feature issues, workaround available

Step 2: Create Hotfix Branch

# Create hotfix branch from the problematic tag
git checkout v1.2.1
git checkout -b hotfix/PROD-789-security-patch

Step 3: Implement Fix

# Implement minimal fix
git add .
git commit -m "fix: Apply security patch for user authentication"
git push origin hotfix/PROD-789-security-patch

Fix Implementation Guidelines:

• Make the smallest possible change to fix the issue
• Strictly bug fixes only - no feature additions
• Add tests that would have caught the issue
• Document the fix and its rationale

Step 4: Merge and Emergency Deploy

# Merge to master
git checkout master
git merge hotfix/PROD-789-security-patch
git push origin master

# Create hotfix tag
git tag -a v1.2.2 -m "Hotfix v1.2.2: Critical security patch"
git push origin v1.2.2

Emergency Deployment:

• May bypass normal approval processes for critical issues
• Enhanced monitoring during and after deployment
• Have immediate rollback plan ready
• Immediate verification that issue is resolved

Automated testing environment deployment for pull requests to validate changes before merging.

Testing Environment Strategy

• Mirrors production configuration with synthetic test data
• Isolated environment automatically provisioned per PR
• Triggered by PR labels (e.g., "deploy-testing") or comments

Automated Deployment Process

# Use PR labels or comments to trigger testing deployment
# Label: "deploy-testing"
# Comment: "/deploy testing"

Environment Provisioning:

• Spin up dedicated testing environment
• Deploy PR branch code with test data
• Run health checks and provide access links
• Comment on PR with deployment status and links

Testing Activities

• Automated Tests: Full test suite against deployed environment
• Manual Testing: Exploratory testing by developers and QA
• Integration Testing: Validate with external test services
• User Acceptance: Business users validate functionality

Pre-production validation in production-like environment after code review approval.

Staging Deployment Criteria

• Code review approved by minimum 2 reviewers
• All automated tests passing
• Testing environment validation completed
• Security review completed (if applicable)
• Senior developer or tech lead approval required

Staging Environment Characteristics

• Production Parity: Mirrors production environment exactly
• Data: Production-like data (anonymized/masked)
• Monitoring: Full monitoring and alerting enabled
• Access: Limited to authorized personnel

Validation Activities

• User acceptance testing by business users
• Full integration with production-like services
• Load testing under realistic conditions
• Security validation in production-like environment
• Data migration testing (if applicable)

Emergency revert process when issues are discovered in staging environment.

Option A: Revert the Merge Commit

# If PR was already merged to master
git checkout master
git revert -m 1 <merge-commit-hash>
git commit -m "Revert: USER-456 due to staging issues"
git push origin master

# Create new tag for emergency revert
git tag -a v1.2.3 -m "Revert v1.2.3: Emergency revert of USER-456"
git push origin v1.2.3

Option B: Hotfix Branch for Revert

# Create hotfix branch to revert changes
git checkout master
git checkout -b hotfix/revert-user-456
git revert <commit-hash>
git push origin hotfix/revert-user-456

# Follow hotfix process for deployment

Post-Revert Activities

• Immediate deployment of reverted code to staging
• Confirm the issue is resolved
• Conduct thorough root cause analysis
• Add tests that would have caught the issue
• Review and improve testing/review processes

Cherry-pick strategy when business decides to release only a subset of features from a release branch.

Situation Assessment

# Check current release branch and its features
git checkout release/v1.3.0
git log --oneline --grep="feat:"

# List all feature branches merged into this release
git log --merges --oneline

Example Scenario:

• Release branch contains 10 features, all tested and ready
• Business decides only 7 features approved for production
• Need selective release while maintaining traceability

Option A: Cherry-pick Approved Features (Recommended)

# Create new release branch for selective features
git checkout master
git pull origin master
git checkout -b release/v1.3.0-selective

# Cherry-pick only approved features in chronological order
git cherry-pick <feature-1-commit>
git cherry-pick <feature-2-commit>
# ... continue for all approved features

Option B: Revert Unwanted Features

# Start with full release and revert unwanted features
git checkout release/v1.3.0
git checkout -b release/v1.3.0-partial
git revert <unwanted-feature-1>
git revert <unwanted-feature-2>
# ... continue for all unwanted features

Key Considerations

• Verify feature interdependencies before selective release
• Run full test suite on the partial feature set
• Update release notes to reflect actual features included
• Communicate changes to all stakeholders

Progressive rollout of features across different environments using feature flags, allowing for controlled exposure and quick rollback.

Step 1: Prepare Feature with Feature Flags

# Deploy feature with flags disabled by default
git checkout master
git pull origin master
git tag -a v1.3.1 -m "Release v1.3.1: New features with feature flags"
git push origin v1.3.1

Feature Flag Implementation:

• Code Implementation: Wrap new features in feature flag conditions
• Configuration Management: Environment-specific flag configurations
• Monitoring Setup: Track feature usage and performance metrics
• Rollback Mechanism: Instant disable capability without redeployment

Step 2: Progressive Environment Enablement

Rollout Strategy:

• Staging 100% enabled for full testing
• UAT 100% enabled for business validation
• Production Progressive rollout (10% → 25% → 50% → 100%)
• Monitoring Real-time metrics and error tracking at each stage

Handle complex dependencies between features developed by different teams that must be coordinated for release.

Step 1: Identify Dependencies

# Team A working on feature/AUTH-123-user-service
# Team B working on feature/UI-456-user-interface  
# Team C working on feature/API-789-user-endpoints
# All three features depend on each other

Dependency Mapping:

• Technical Dependencies: Code-level dependencies between features
• Business Dependencies: Features that must be released together
• Timeline Dependencies: Features with specific sequencing requirements
• Integration Points: Shared APIs, databases, or services

Step 2: Coordinate Integration Branch

# Create integration branch for cross-team coordination
git checkout master
git pull origin master
git checkout -b integration/user-management-release

# Teams merge their features into integration branch
git merge feature/AUTH-123-user-service
git merge feature/UI-456-user-interface
git merge feature/API-789-user-endpoints

Integration Process:

• Integration Branch: Dedicated branch for coordinating dependent features
• Regular Syncing: Daily merges from individual feature branches
• Conflict Resolution: Immediate resolution of integration conflicts
• Joint Testing: Cross-team testing in integration environment

Apply critical patches while a regular release is in progress, requiring careful coordination.

Step 1: Assess Conflict Between Emergency and Regular Release

Current State:

• release/v1.4.0 branch in UAT testing phase
• Critical security issue found in production v1.3.5
• Need emergency patch without disrupting regular release

Conflict Assessment:

• Timeline Conflict Emergency patch vs. scheduled release
• Code Conflict Potential overlapping changes
• Resource Conflict Team availability and focus

Step 2: Parallel Track Strategy

# Create hotfix from current production
git checkout v1.3.5
git checkout -b hotfix/SECURITY-001-critical-patch

# Implement and test hotfix
git add .
git commit -m "fix: Critical security patch"
git push origin hotfix/SECURITY-001-critical-patch

# Deploy hotfix immediately
git checkout master
git merge hotfix/SECURITY-001-critical-patch
git tag -a v1.3.6 -m "Hotfix v1.3.6: Critical security patch"
git push origin v1.3.6

Step 3: Integrate Hotfix into Active Release

# Merge hotfix into active release branch
git checkout release/v1.4.0
git merge hotfix/SECURITY-001-critical-patch
git push origin release/v1.4.0

# Re-test release with hotfix included
# Continue with regular release process

Handle complex database migrations that require careful coordination between code deployment and schema changes.

Step 1: Assess Migration Complexity

Migration Strategy:

• Backward Compatibility: Ensure old code works with new schema temporarily
• Multi-Phase Deployment: Separate schema and application deployment phases
• Rollback Planning: Prepare rollback scripts for each migration step
• Data Preservation: Ensure no data loss during migration or rollback

Step 2: Implement Phased Migration

# Phase 1: Add new columns (backward compatible)
git checkout release/v1.4.0
git tag -a v1.4.0-schema -m "Database schema migration phase 1"

# Phase 2: Deploy application code using new schema
git tag -a v1.4.0 -m "Application deployment with new schema support"

# Phase 3: Remove old columns (after validation)
git tag -a v1.4.1 -m "Schema cleanup - remove deprecated columns"

Migration Example:

• Phase 1: ALTER TABLE users ADD COLUMN new_field VARCHAR(255) DEFAULT NULL;
• Phase 2: Deploy application that can use both old and new columns
• Phase 3: ALTER TABLE users DROP COLUMN old_field;

Handle complex merge conflicts that arise when multiple large features are integrated simultaneously.

Step 1: Identify Conflict Scope

# Multiple features causing complex conflicts
git checkout release/v1.6.0
git merge feature/LARGE-FEATURE-A
# Conflicts detected
git merge --abort

# Analyze conflict scope
git merge-tree $(git merge-base feature/LARGE-FEATURE-A release/v1.6.0) feature/LARGE-FEATURE-A release/v1.6.0

Conflict Analysis:

• File-level Conflicts: Which files have overlapping changes
• Functional Conflicts: Logical conflicts in business logic
• Architectural Conflicts: Conflicting architectural decisions
• Test Conflicts: Overlapping or conflicting test cases

Step 2: Systematic Conflict Resolution

# Create conflict resolution branch
git checkout release/v1.6.0
git checkout -b integration/conflict-resolution

# Merge features one by one
git merge feature/LARGE-FEATURE-A
# Resolve conflicts carefully
git add .
git commit -m "Resolve conflicts for LARGE-FEATURE-A"

git merge feature/LARGE-FEATURE-B
# Resolve additional conflicts
git add .
git commit -m "Resolve conflicts for LARGE-FEATURE-B"

Resolution Strategy:

• Sequential Integration: Merge features one at a time
• Expert Consultation: Involve original feature developers
• Comprehensive Testing: Test after each conflict resolution
• Documentation: Document resolution decisions for future reference

Maintain detailed audit trails and compliance requirements throughout the development and deployment process.

Step 1: Establish Audit Requirements

Audit Trail Components:

• Requirements Traceability: Link every commit to business requirement
• Approval Documentation: Record all review and approval decisions
• Deployment History: Maintain complete deployment timeline
• Change Impact Analysis: Document potential impacts of each change

Step 2: Implement Compliance Workflow

# Enhanced commit message format for traceability
git commit -m "feat: USER-123 - Add user authentication

Business Requirement: REQ-456
Approved by: John Doe (Product Owner)
Technical Review: Jane Smith (Tech Lead)  
Security Review: Bob Johnson (Security Team)
Impact: New feature, no breaking changes"

Step 3: Digital Signatures for Releases

# Tag releases with compliance information
git tag -s v1.6.0 -m "Release v1.6.0 - Compliance validated

Features: USER-123, USER-124, USER-125
Compliance Officer: Alice Brown
Deployment Window: 2025-07-24 10:00-12:00 UTC
Rollback Tested: Yes
Risk Level: Medium"

Handle coordinated deployments across multiple geographic regions with different maintenance windows.

Step 1: Plan Multi-Region Strategy

Deployment Regions:

• US East Primary - Deploy first
• EU West Deploy 2 hours later
• Asia Pacific Deploy 4 hours later

Regional Considerations:

• Time Zone Coordination: Plan deployments during local maintenance windows
• Sequential Deployment: Deploy to regions in planned sequence
• Regional Rollback: Ability to rollback specific regions independently
• Data Consistency: Ensure data synchronization across regions

Step 2: Implement Regional Deployment

# Create region-specific tags
git tag -a v1.8.0-us-east -m "Deploy to US East region"
git push origin v1.8.0-us-east

# Monitor US East deployment, then proceed
# 2 hours later
git tag -a v1.8.0-eu-west -m "Deploy to EU West region"
git push origin v1.8.0-eu-west

# Monitor EU West deployment, then proceed  
# 2 hours later
git tag -a v1.8.0-asia-pacific -m "Deploy to Asia Pacific region"
git push origin v1.8.0-asia-pacific

Handle updates to third-party dependencies and vendor integrations that require careful testing and validation.

Step 1: Assess Third-Party Impact

Impact Assessment:

• API Compatibility: Test all integration points
• Security Implications: Validate new security requirements
• Compliance Requirements: Ensure continued regulatory compliance
• Performance Impact: Measure performance changes

Step 2: Coordinate Vendor Integration

# Create vendor integration branch
git checkout master
git checkout -b integration/vendor-payment-v2

# Update vendor SDKs and APIs
# Implement required security changes
# Update compliance handling

# Extensive testing in vendor sandbox environment
# Coordinate with vendor for production cutover

Integration Process:

• Sandbox Testing: Comprehensive testing in vendor test environment
• Gradual Migration: Phase migration from old to new vendor APIs
• Fallback Planning: Maintain ability to revert to previous vendor version
• Monitoring: Enhanced monitoring during vendor integration

Environment	Purpose	Trigger	Approval Required
Development	Feature development and unit testing	Feature branch push	None
Testing	Integration and system testing	PR creation	None
Staging	User acceptance testing	Merge to master	Tech Lead
Production	Live system	Version tag	Release Manager + Business

# 1. Development to Testing (Automatic)
git push origin feature/USER-123
# Triggers testing deployment

# 2. Testing to Staging (After PR merge)
git checkout master
git merge feature/USER-123
git push origin master
# Triggers staging deployment

# 3. Staging to Production (Manual tag)
git tag -a v1.2.0 -m "Release v1.2.0: User authentication"
git push origin v1.2.0
# Triggers production deployment after approval

Commit Messages

Follow conventional commits format:

type(scope): description

feat: add new authentication system
fix: resolve memory leak in user service
docs: update API documentation
chore: update dependencies

Branch Protection Rules

• Require pull request reviews (minimum 2)
• Require status checks to pass before merging
• Require branches to be up to date before merging
• Restrict who can push to matching branches
• Require signed commits for audit trail
• Dismiss stale reviews when new commits are pushed

Security Best Practices

• Signed Commits Enforce GPG signing for all commits
• Secret Scanning Automated scanning for exposed secrets
• Access Control Role-based access with principle of least privilege
• Audit Logging Complete audit trail of all Git operations

Performance Optimization

• Shallow Clones: Use --depth for CI/CD to reduce clone time
• Partial Clones: Use --filter for large repositories
• Git LFS: Store large files in Git LFS
• Packfile Optimization: Regular maintenance with git gc
• Reference Repositories: Use reference repos for faster clones

Advanced Git Configuration

# Enforce commit message standards
git config --global commit.template .gitmessage

# Configure advanced merge strategies
git config --global merge.tool vimdiff
git config --global merge.conflictstyle diff3

# Enable rerere for repeated conflict resolution
git config --global rerere.enabled true

# Configure hooks path
git config --global core.hooksPath .githooks

Monitoring and Observability

Key Metrics to Monitor:

• Deployment Frequency How often deployments occur
• Lead Time Time from commit to production
• MTTR Mean time to recovery from incidents
• Change Failure Rate Percentage of deployments causing failures

1. Quick Rollback (Tag-based)

# Rollback to previous stable version
git tag v2.0.1-rollback
git push origin v2.0.1-rollback
# Trigger deployment pipeline

2. Hotfix Rollback

# Create hotfix branch from last stable tag
git checkout v2.0.0
git checkout -b hotfix/v2.0.1-emergency-fix

# Apply minimal fix
git commit -m "fix: critical security patch"

# Tag and deploy
git tag v2.0.1
git push origin v2.0.1

Merge Conflicts

# Update feature branch with latest main
git checkout feature/branch-name
git fetch origin
git rebase origin/main

# Resolve conflicts, then continue
git add .
git rebase --continue

Failed CI/CD Pipeline

Solution: Check pipeline logs, fix issues in feature branch, and re-run pipeline. Never skip CI checks for main branch.