What Is the Best CI for Large Engineering Teams?
Usually the CI built into the platform that hosts your code, such as GitHub Actions for GitHub, paired with a runner layer built for queue time, cost per team, SSO and data residency.
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What is the best CI for a large engineering team?
The best CI for a large team is usually the one built into the platform where your code already lives. For code on GitHub, that is GitHub Actions. Then pair it with a runner layer such as WarpBuild that is built for scale: no queueing under load, cost per team, SSO, data residency and runners in your own cloud account.
Moving CI platforms means rewriting every pipeline and retraining every team. Most of the problems that show up at scale are about the machines that run jobs, not the CI platform that schedules them. In GitHub Actions, the runs-on label on each job decides which runner it uses. So you can change runners one job at a time without leaving the platform.
Which CI platforms do large teams choose between?
Large teams usually choose between GitHub Actions, GitLab CI/CD, Buildkite, CircleCI and Jenkins. The table compares the facts that matter at scale: where the platform runs, where the build machines come from, and how sign-in is controlled.
| Platform | Where the platform runs | Where build machines come from | SSO or self-managed edition |
|---|---|---|---|
| GitHub Actions | GitHub.com, or GitHub Enterprise Server, a self-hosted version you run on your own VMs on-premises or on AWS, GCP or Azure | GitHub-hosted runners on Ubuntu, Windows or macOS, or self-hosted runners at repository, organization or enterprise level | SAML SSO for enterprises on GitHub Enterprise Cloud |
| GitLab CI/CD | GitLab.com, GitLab Dedicated, or GitLab Self-Managed, which you install on Linux, cloud providers or Kubernetes | GitLab-hosted runners on GitLab.com and GitLab Dedicated, or self-managed runners on your own infrastructure on all three offerings | SAML SSO for GitLab.com groups on Premium and Ultimate. SAML on Self-Managed on Free, Premium and Ultimate |
| Buildkite | Buildkite runs the control plane (architecture) | Agents you run in your own environment, or Buildkite hosted agents on Linux, macOS and Windows | SSO on Pro and Enterprise plans. Custom SAML on Enterprise |
| CircleCI | CircleCI cloud, or CircleCI Server, an on-premises edition that runs in your Kubernetes cluster | CircleCI cloud machines, or the self-hosted runner on your own infrastructure, with cloud or Server | SAML SSO for Scale plan customers |
| Jenkins | Self-managed. You install and run it yourself | Agents on nodes that your team sets up and the controller manages | Built-in user database, LDAP, or SAML through a plugin |
Where your code is hosted usually decides the platform. GitHub Actions is part of GitHub and GitLab CI/CD is part of GitLab, so teams on those platforms add no second CI vendor. Buildkite, CircleCI and Jenkins are separate products, so they need their own accounts and access control.
What breaks first as a team grows?
On GitHub Actions, the first things to break are usually queue time, cost visibility and access control. Data residency and GitHub Enterprise Server support come next. These are runner problems, so each one can be fixed without moving off GitHub Actions.
| Problem at scale | What causes it | What a runner layer such as WarpBuild changes |
|---|---|---|
| Queue time | Standard GitHub-hosted runners have a concurrent job limit per plan: 20 on Free, 40 on Pro, 60 on Team and 500 on Enterprise, with a lower macOS limit. Larger runners allow up to 1,000 on Team and Enterprise. GitHub lists these under "Job concurrency limits for GitHub-hosted runners" (GitHub usage limits) | WarpBuild's generally available Linux and Windows runners have unlimited concurrency. High concurrency on macOS goes through [email protected] (cloud runners docs) |
| Cost per repository and team | GitHub's usage report shows usage by SKU, organization, repository and workflow path, but has no job name or runner label field. In the summarized report, teams that share one repository share one line | WarpBuild's billing report has one row per job with repository, job name, runner label, stack and cost. BYOC (WarpBuild-managed runners in your own cloud account, unlike self-hosted runners your team operates) adds custom tags on the stack that you can group by in AWS cost reports (AWS stack config). On GCP, group by project. On Azure, group by subscription |
| Access control and SSO | More people need dashboard access, and identity teams want one sign-in | SAML 2.0 and OIDC single sign-on (SSO docs), available as an add-on ($250 per month, pricing) |
| Data residency | Security reviews ask where build data is stored | On WarpBuild enterprise plans, region-specific infrastructure keeps the data you choose in one region, except macOS (cloud runners docs). Data residency is available as an add-on ($250 per month, pricing). BYOC keeps runners and caches in your own account |
| GitHub Enterprise Server | Runners must connect to your own enterprise host instead of GitHub.com | Available on the WarpBuild Enterprise plan. Runners connect to GitHub Enterprise Server and to GitHub Enterprise Cloud with data residency (ghe.com) (GHE docs) |
To find where your own queue time comes from, see diagnosing GitHub Actions queue times. For the full chargeback setup, see attributing GitHub Actions cost per repository and team.
Managed, BYOC or self-hosted runners: which fits which team?
Managed runners fit teams that want no infrastructure work. BYOC fits teams that must keep runners in their own cloud account. Self-hosted runners fit teams that want full control and have people to run the fleet. All three work with GitHub Actions through the runs-on label.
| Runner model | Where runners run | Who operates scaling and images | What you pay | Fits |
|---|---|---|---|---|
| Managed (WarpBuild cloud runners) | WarpBuild infrastructure | Fully managed for you | Per-minute rate per runner size (pricing) | Teams that want faster runners and no fleet to run |
| BYOC (WarpBuild in your cloud) | Your own AWS, GCP or Azure account (BYOC docs) | WarpBuild runs the control plane. You own the account, quotas and network | $0.002 per runner minute, plus compute, storage and transfer on your own cloud bill (BYOC cost model) | Teams with data residency rules, cloud discounts they already hold, or private network access needs |
| Self-hosted, for example Actions Runner Controller (ARC) | Your own Kubernetes cluster or VMs | Your team | Your cloud bill plus the engineering time to run it | Teams with a platform team that wants full control |
BYOC and self-hosted runners both run in infrastructure you control. The difference is who operates it. With BYOC, WarpBuild starts and stops runner VMs in your account. With self-hosted runners, your team does that work. Actions Runner Controller (ARC) is a Kubernetes operator that orchestrates and scales self-hosted runners for GitHub Actions. What Self-Hosted Runners Actually Cost prices the engineering time, and choosing between hosted and BYOC runners covers the first two models in more detail.
Where can I compare runner vendors?
The runner comparison hub lists side-by-side comparisons of GitHub Actions runner providers. For a direct comparison with GitHub's own runners, read WarpBuild vs GitHub-hosted runners. To see the other options for running GitHub Actions jobs, read alternatives to GitHub-hosted runners. Teams already running ARC can follow migrating from ARC to WarpBuild.
FAQ
What is the best CI for a large engineering team?
Usually the CI built into the platform where your code already lives, such as GitHub Actions for code on GitHub. At scale the runner layer matters as much as the CI platform. Pick runners that do not queue under load, report cost per repository and team, support SSO and data residency, and can run in your own cloud account.
Do large teams need to leave GitHub Actions to fix slow or expensive CI?
Usually not. Queue time, cost attribution and placement are runner problems. Changing the runs-on label on a job moves it to a different runner, and the workflow files stay the same. WarpBuild managed and BYOC runners, as well as self-hosted runners, all work with GitHub Actions.
What is the difference between BYOC and self-hosted runners?
Both run in infrastructure you control. With BYOC, WarpBuild runs the control plane and starts and stops runner VMs in your own AWS, GCP or Azure account. With self-hosted runners, for example on Actions Runner Controller, your team operates the scaling, images and upgrades as well.
Does GitHub Actions work with GitHub Enterprise Server?
Yes. GitHub Enterprise Server is the self-hosted version of GitHub, and it includes GitHub Actions. A site administrator turns Actions on, and workflows run on self-hosted runners because GitHub-hosted runners are not supported on GitHub Enterprise Server (https://docs.github.com/en/enterprise-server@latest/admin/managing-github-actions-for-your-enterprise/getting-started-with-github-actions-for-your-enterprise/getting-started-with-github-actions-for-github-enterprise-server). On the WarpBuild Enterprise plan, runners connect to GitHub Enterprise Server and GitHub Enterprise Cloud with data residency, through a GitHub App you register on your own enterprise.
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Change the runner label in your workflow and keep the rest of your GitHub Actions setup. Runner time is billed per minute.