A Phased Migration from Azure DevOps Server to GitHub Enterprise Cloud.

Moving a Complex Development and Data Environment to GitHub.

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Across a 272-hour engagement, InfoMagnus is helping a California county health department move from Azure DevOps Server to GitHub Enterprise Cloud with Enterprise Managed Users.

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The environment spans roughly 226 repositories managed by a five-person Developer team and a 35-person DBA team.

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It includes application code, reporting assets, data workflows, and monorepos as large as 14 GB. The migration also includes GitHub Actions enablement and role-based training for both teams.

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Business Challenge: Migrating a Large, Mixed-Stack Environment Without Disrupting Two Very Different Teams.

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The health department needed to move its source code, history, and CI/CD practices off an on-premises Azure DevOps 2022 instance and into GitHub Enterprise Cloud under an EMU tenant. The environment made a straightforward lift-and-shift impractical:

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• Very large monorepos, up to approximately 14 GB, risked transfer failures and history loss if migrated using default tooling.
• The repository base split across two audiences with different needs: a small Developer team already comfortable with GitHub, and a much larger, 35-person DBA team supporting data-centric repos (RDL, DTSX) who were less familiar with GitHub-native workflows.
• Azure DevOps constructs: repositories, branches, permissions, and pipelines, had to be mapped to GitHub equivalents rather than copied directly.
• CI/CD needed to be rebuilt on GitHub Actions, including support for workloads that required self-hosted runners.

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Without a structured plan for sequencing, remediation, and training, the health department risked a stalled or incomplete migration, particularly for its largest and most complex repositories.

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Solution Overview: A Phased Migration Paired With Role-Based Enablement.

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InfoMagnus scoped and executed the migration in coordination with health department stakeholders and InfoMagnus delivery and engagement managers.

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The work combined hands-on migration with targeted training so both the Developer and DBA teams could operate confidently in the new environment as repositories came online.

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Migration Execution:

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• Planned and executed repository moves from Azure DevOps into the GitHub EMU tenant, preserving history and metadata where required.
• Addressed the complications introduced by very large monorepos, including remediation and special handling recommendations for repos that could not transfer using default methods.
• Mapped Azure DevOps repos, branches, permissions, and pipelines to their GitHub equivalents.

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CI/CD Enablement:

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• Stood up initial GitHub Actions infrastructure, including support for self-hosted runners where the health department's workloads required them.
• Accounted for data-centric workflows and repo size constraints when designing pipeline configurations.

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Training & Enablement:

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• GitHub Actions Training, covering CI/CD patterns for the new environment.
• GitHub Admin Training for GitHub Enterprise Cloud (GHEC/EMU), covering configuration and governance.
• GitHub for Developers Training, focused on best practices for working with large repositories and data pipeline code.
• Workshops were tailored separately for the Developer and DBA audiences to match their existing familiarity with GitHub.

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This is a phased, in-progress engagement: several repositories and a subset of Actions workflows are live today, with a documented plan in place to complete the remaining migration scope.

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Key Benefits.

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By this stage of the engagement, the health department has received:

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• Repositories successfully migrated into the GitHub EMU tenant, with history and metadata preserved.
• GitHub Actions workflows running in production on self-hosted runners.
• Role-based training delivered to both the Developer and DBA teams across Actions, Admin, and Developer curricula.
• Azure DevOps repos, branches, permissions, and pipelines mapped to GitHub-native equivalents.
• A documented, sequenced plan for completing the remaining migration scope.

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As the remaining scope is completed, the health department is positioned to:

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• Finish migrating the remaining repositories, with particular attention to the largest monorepos and DB/ETL-related repos.
• Optimize CI/CD pipelines for data-centric workflows.
• Finalize permission and governance policies across the GitHub EMU tenant.
• Complete knowledge transfer to the health department's operations staff.

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Future Outlook.

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Migrating a mixed development and data environment, spanning application code, reporting artifacts, and ETL pipelines, requires more than a single generic playbook.

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As the health department completes the remaining migration scope, the groundwork laid during this phase gives both the Developer and DBA teams a consistent, GitHub-native foundation for source control, CI/CD, and governance going forward.