GitHub Actions

\[VISUAL: Hero screenshot of the GitHub Actions workflow editor with a running pipeline\]

\[VISUAL: Table of Contents - Sticky sidebar with clickable sections\]

1. Introduction: CI/CD That Lives Where Your Code Already Does

I've been running GitHub Actions across seven repositories for over eighteen months now, handling everything from simple linting jobs to complex multi-environment deployments with matrix builds across three operating systems. The promise is seductive: CI/CD that lives directly inside your code repository with zero context switching and zero additional vendor accounts.

After pushing roughly 4,000 commits through Actions pipelines, debugging more YAML indentation errors than I care to admit, and migrating two projects away from [Jenkins](/reviews/jenkins) and one from [CircleCI](/reviews/circleci), I can tell you precisely where GitHub Actions delivers brilliantly and where it will make you question your career choices.

My evaluation framework covers ten dimensions: ease of setup, workflow flexibility, marketplace ecosystem, performance and speed, pricing transparency, security posture, scalability, debugging experience, documentation quality, and ecosystem lock-in risk. GitHub Actions scores unevenly across these areas, which is what makes this review worth reading rather than just checking the marketing page.

For context, I work with a team of eight developers shipping a SaaS product with a Next.js frontend, Python microservices backend, and infrastructure managed through Terraform. We run approximately 150 workflow executions per day across staging and production environments.

2. What Is GitHub Actions? Understanding the Platform

\[VISUAL: Architecture diagram showing how GitHub Actions fits into the GitHub ecosystem - repositories, events, workflows, runners\]

GitHub Actions is a CI/CD and workflow automation platform built directly into GitHub. Launched in November 2019 after a beta period, it allows you to define automated workflows that trigger in response to events in your repository: pushes, pull requests, issue creation, scheduled cron jobs, or even manual dispatches.

The platform operates on a straightforward concept. You write YAML files that live in your repository's `.github/workflows/` directory. Each file defines a workflow consisting of one or more jobs, and each job runs on a virtual machine called a runner. Jobs contain steps, which are individual commands or references to pre-built actions from the marketplace.

What separates GitHub Actions from standalone CI/CD tools is its native integration with the GitHub ecosystem. Pull request checks, deployment environments with approval gates, issue automation, and release management all operate without leaving the platform. There is no webhook configuration, no OAuth dance, and no token management to connect your CI system to your repository.

GitHub, owned by Microsoft since 2018, serves over 100 million developers and hosts more than 330 million repositories. Actions benefits from this scale with a marketplace containing over 16,000 community-built actions and runner infrastructure distributed across multiple cloud regions.

\[VISUAL: Timeline showing GitHub Actions evolution from 2019 beta to current feature set including reusable workflows, composite actions, and larger runners\]

Platform & Availability

3. GitHub Actions Pricing & Plans: Complete Breakdown

\[VISUAL: Interactive pricing calculator widget - users input team size and expected minutes to see monthly costs\]

GitHub Actions pricing ties directly to your GitHub plan, and understanding the included minutes versus overage rates is critical to avoiding bill shock.

3.1 Free Plan - Generous for Open Source, Tight for Private

\[SCREENSHOT: GitHub Free plan settings showing Actions minutes usage meter\]

GitHub Actions is completely free for public repositories with no minute limits. This alone makes it the default choice for open source projects. For private repositories on the Free plan, you get 2,000 minutes per month and 500MB of Actions storage.

What's Included: Linux, Windows, and macOS runners. Access to the full marketplace. Secrets management. Caching (10GB per repository). Artifacts storage. Manual workflow dispatch. Scheduled workflows. Matrix builds. All workflow features are available regardless of plan.

Key Limitations: The 2,000 minutes sound generous until you realize that Windows minutes consume at 2x rate and macOS minutes at 10x. A workflow running 10 minutes on macOS eats 100 of your 2,000 minutes. Concurrency is limited to 20 jobs. No larger runner options. No environment protection rules for deployment approvals.

3.2 Team Plan ($4/user/month) - The Professional Tier

The Team plan adds 3,000 minutes per month for private repositories and 2GB of storage. More importantly, it unlocks features that matter for professional teams.

Key Upgrades: Environment protection rules let you require approvals before deployments proceed. Required reviewers on environments add a human gate to your pipeline. Deployment branches restrict which branches can target production. You also get access to larger runners (up to 64 cores) for compute-heavy builds.

3.3 Enterprise Plan ($21/user/month) - Full Control

Enterprise jumps to 50,000 included minutes and 50GB of storage. The real value lies in governance and compliance features.

Enterprise Exclusives: SAML single sign-on. Audit log API access. IP allow lists for runners. Internal repositories (visible to org members only). GitHub Connect for hybrid deployments. Advanced security features including code scanning and secret scanning with push protection. Dedicated support with SLA guarantees.

3.4 Overage Pricing - Where Costs Sneak Up

\[VISUAL: Cost comparison chart showing per-minute rates across Linux, Windows, and macOS\]

When you exceed included minutes, overage rates apply per minute of execution:

4. Key Features Deep Dive

4.1 YAML Workflow Definitions - Power Through Declarative Config

\[SCREENSHOT: Side-by-side view of a workflow YAML file and its visual representation in the Actions tab\]

Everything in GitHub Actions starts with YAML files in your `.github/workflows/` directory. This declarative approach means your CI/CD configuration lives alongside your code, versioned, reviewable, and portable.

A workflow file defines triggers (the `on:` block), jobs (parallel or sequential units of work), and steps within each job. The syntax is expressive enough to handle complex scenarios while remaining readable for newcomers. Conditional execution using `if:` expressions lets you skip steps based on branch names, labels, or custom conditions.

I initially resisted YAML-based configuration after years of Jenkins' UI-based pipelines. Within a week, I was converted. Being able to review CI/CD changes in the same pull request as the code changes they support eliminates an entire category of "it works on my machine but breaks in CI" problems.

The learning curve is real, though. YAML indentation errors produce cryptic failures. Complex expression syntax like `${{ github.event.pull_request.head.ref }}` is powerful but ugly. And debugging a workflow that works locally but fails in Actions requires patience and liberal use of debug logging.

4.2 Marketplace Ecosystem - 16,000+ Pre-Built Actions

\[SCREENSHOT: GitHub Actions Marketplace showing popular actions with download counts and verification badges\]

The Actions Marketplace is GitHub's secret weapon. With over 16,000 community-built actions, you rarely need to write CI/CD logic from scratch. Need to deploy to AWS? There is an official action. Set up Node.js? One line. Send a Slack notification? Dozens of options. Run Terraform? Multiple well-maintained actions compete for your attention.

Actions are referenced by repository and version tag, meaning you can pin to a specific commit SHA for security or follow a major version tag for convenience. The `uses:` syntax makes consuming actions trivially simple: `uses: actions/checkout@v4` checks out your code. `uses: actions/setup-node@v4` configures Node.js. The composability is elegant.

During our migration from Jenkins, we replaced 2,000 lines of Groovy pipeline scripts with 200 lines of YAML referencing marketplace actions. The maintenance burden dropped dramatically because action maintainers handle updates rather than our team maintaining custom scripts.

4.3 Matrix Builds - Test Everything, Everywhere, At Once

\[VISUAL: Diagram showing a matrix build expanding across 3 OS versions and 4 language versions = 12 parallel jobs\]

Matrix builds are one of GitHub Actions' most powerful features for testing across multiple configurations. Define a matrix of variables - operating systems, language versions, dependency versions - and Actions automatically creates a job for every combination.

A single matrix definition can spin up dozens of parallel jobs testing your code against Node 18, 20, and 22 on Ubuntu, Windows, and macOS simultaneously. Include/exclude rules let you customize the matrix for edge cases, like skipping a known-incompatible combination or adding extra configuration to specific entries.

We use matrix builds to test our Python services against Python 3.10, 3.11, and 3.12 with both PostgreSQL 14 and 16. That is six combinations running in parallel, completing in the time of the slowest single run rather than six sequential runs. What used to take 45 minutes on Jenkins takes 8 minutes on Actions.

4.4 Self-Hosted Runners - Bring Your Own Hardware

\[SCREENSHOT: Self-hosted runner configuration page showing connected runners with status indicators\]

Self-hosted runners let you execute workflows on your own infrastructure. This solves three problems: cost (no per-minute charges), performance (use beefier hardware), and access (reach private networks and specialized hardware).

Setting up a self-hosted runner involves downloading the runner application and registering it with your repository or organization. The runner polls GitHub for jobs and executes them locally. You can run it on bare metal, virtual machines, Kubernetes pods, or even Raspberry Pis. Runner groups let you organize runners by capability and assign them to specific workflows.

Our team runs four self-hosted runners on a dedicated build server: two for general CI jobs and two with GPU access for machine learning model validation. The GPU runners alone save us hundreds of dollars monthly compared to what cloud GPU instances would cost.

4.5 Reusable Workflows and Composite Actions - DRY Your Pipelines

\[VISUAL: Diagram showing a reusable workflow being called from three different repository workflows\]

As your organization grows, duplicating workflow logic across repositories becomes a maintenance nightmare. Reusable workflows and composite actions solve this by enabling shared, centralized CI/CD components.

Reusable workflows are complete workflow files that other workflows call using the `uses:` keyword, similar to function calls. They accept inputs and secrets, run their jobs, and return outputs. We maintain a central `.github` repository containing our standard deployment workflow, security scanning pipeline, and release process. Every repository references these instead of maintaining its own copy.

Composite actions bundle multiple steps into a single reusable action. Unlike reusable workflows, composite actions run within the calling job rather than spawning new jobs. They are ideal for packaging common step sequences like "install dependencies, build, and upload artifacts."

5. GitHub Actions Pros: What Makes It Shine

\[VISUAL: Pros summary infographic highlighting key strengths with icons\]

Seamless GitHub Integration

The single greatest advantage of GitHub Actions is that it is not a separate tool. There is no integration to configure, no webhook to set up, no external dashboard to check. Workflow status appears directly on pull requests. Deployment environments show in the repository sidebar. Secrets live in repository settings. Everything is one click away from your code.

This integration extends to GitHub's permission model. Repository collaborators automatically have appropriate CI/CD access. Branch protection rules can require workflow checks to pass before merging. Environment protection rules add deployment approval gates. The security model is inherited rather than duplicated.

After using Jenkins for three years where every repository required webhook configuration, credential management, and plugin maintenance, the "it just works" nature of Actions felt like a revelation.

Unmatched Open Source Support

Free unlimited minutes for public repositories with no restrictions on features or runner types. This policy has made GitHub Actions the de facto CI/CD platform for open source. Major projects like React, Kubernetes, and VS Code all run on Actions.

The community benefits compound: more open source projects using Actions means more marketplace actions, better documentation, more Stack Overflow answers, and faster bug fixes. The ecosystem flywheel is real and accelerating.

Marketplace Depth and Quality

Over 16,000 actions covering virtually every common CI/CD task. Official actions from GitHub cover the fundamentals. Verified creators provide quality assurance for popular third-party actions. The barrier to creating and sharing actions is low, encouraging community contribution.

Configuration as Code

Workflows live in your repository as YAML files. They are version-controlled, reviewable in pull requests, and portable. When I need to understand why a deployment behaved differently last month, I check the git history of the workflow file. When a new team member wants to understand our CI pipeline, they read the YAML. No hidden UI configurations or server-side state to discover.

Rapid Iteration Speed

Starting a new workflow takes minutes, not days. Create a YAML file, push it, and watch it run. The feedback loop between writing a workflow and seeing results is fast enough to iterate comfortably. Compared to Jenkins where setting up a new pipeline involved server configuration, plugin installation, and credential management, Actions removes nearly all friction.

6. GitHub Actions Cons: The Pain Points

\[VISUAL: Cons summary infographic highlighting main pain points\]

Debugging is Genuinely Painful

When a workflow fails, you are staring at log output in a web browser. There is no interactive debugger, no SSH-into-the-runner option (without third-party actions), and no way to reproduce the exact runner environment locally. The `act` tool attempts local execution but cannot replicate the full GitHub runner environment.

Failed workflows require the push-wait-check cycle: modify the YAML, commit, push, wait for the runner, check logs, repeat. A complex debugging session can involve dozens of commits with messages like "debug: try fixing path" and "debug: add more logging." This is the single most frustrating aspect of the platform.

YAML Complexity at Scale

Simple workflows are simple. Complex workflows become YAML nightmares. Deeply nested conditionals, expression syntax with double curly braces, context object references, and matrix configurations create files that are technically readable but practically inscrutable.

Our most complex deployment workflow is 450 lines of YAML. Understanding what it does requires knowledge of GitHub Actions expression syntax, the event payload structure, and dozens of marketplace action configurations. New team members are intimidated. Experienced team members still make mistakes.

macOS Runner Costs

At 10x the Linux rate, macOS runners make iOS and macOS development expensive on Actions. A team running regular iOS builds can easily spend more on Actions overages than on a dedicated Mac Mini build server. This pricing pushes mobile teams toward self-hosted runners or alternative platforms.

Limited Workflow Debugging Tools

Beyond log output, GitHub provides minimal debugging support. No built-in way to re-run a single failed step. No workflow visualization that shows data flow between jobs. No diff view showing what changed between a passing and failing run. The recent addition of step-level re-runs helped, but the debugging experience remains primitive compared to modern CI platforms.

Vendor Lock-In Reality

While workflow YAML is technically portable, the reality is different. Marketplace action references, GitHub-specific context variables, and integration with GitHub features like environments and deployment status create deep coupling. Migrating away from Actions means rewriting workflows, not just moving files. We learned this when evaluating a move to [GitLab](/reviews/gitlab) for one project - every workflow needed significant rewriting.

7. Setup & Implementation Requirements

\[VISUAL: Implementation timeline showing phases from first workflow to full CI/CD maturity\]

The Real Timeline

Getting started with GitHub Actions is deceptively fast. Your first workflow can run within minutes. Reaching production-grade CI/CD maturity takes considerably longer.

Day 1-2: First Workflows Create a basic CI workflow that runs tests on pull requests. The GitHub UI offers starter templates for most languages. Initial success comes quickly and builds confidence.

Week 1: Core Pipeline Build out the full CI pipeline with linting, testing, building, and artifact creation. Configure branch protection rules to require checks. Set up secrets for external service credentials. Implement caching to speed up builds.

Week 2-3: Deployment Automation Create deployment workflows targeting staging and production environments. Configure environment protection rules with required reviewers. Set up deployment status notifications. Implement rollback workflows.

Week 4-6: Optimization and Scaling Add matrix builds for cross-platform testing. Extract reusable workflows for shared logic. Implement self-hosted runners if cost or performance warrants it. Fine-tune caching strategies. Create composite actions for common step patterns.

8. Competitor Comparison: GitHub Actions vs. Alternatives

\[VISUAL: Comparison matrix with color-coded ratings across all competitors\]

vs. GitLab CI/CD

GitLab CI/CD is the closest direct competitor and arguably more mature in several areas. GitLab's pipeline visualization is superior, showing job dependencies and data flow graphically. The debugging experience is better with interactive web terminals into running jobs. Auto DevOps provides convention-over-configuration deployments that Actions lacks.

However, GitLab CI requires using GitLab as your source control platform. If your code lives on GitHub, using GitLab CI means mirroring repositories or migrating entirely. The free tier offers only 400 compute minutes compared to Actions' 2,000. For teams already on GitHub, the friction of adopting GitLab CI rarely justifies its advantages.

vs. CircleCI

CircleCI offers a more polished CI/CD experience with better caching, superior debugging with SSH access to build environments, and a credit-based pricing model that some teams find more predictable. CircleCI's orbs (reusable config packages) are better documented and more standardized than Actions' marketplace.

The tradeoff is adding another tool to your stack. CircleCI requires separate account management, webhook configuration, and context switching between your repository and CI dashboard. For teams that value a unified experience, this friction matters. CircleCI also suffered a significant security breach in January 2023 that shook user confidence.

vs. Jenkins

Jenkins remains the most flexible CI/CD platform available. With 1,800+ plugins, it can do virtually anything. But that flexibility comes with massive operational overhead: server management, plugin compatibility issues, Groovy pipeline syntax, and security patching.

We migrated from Jenkins to GitHub Actions specifically to eliminate the Jenkins maintenance burden. Our DevOps engineer spent roughly 15% of their time maintaining Jenkins. After migrating, that time dropped to near zero. The loss in flexibility was more than offset by the reduction in operational toil.

vs. Bitbucket Pipelines

Bitbucket Pipelines offers the same "CI/CD integrated with your SCM" value proposition as GitHub Actions, but for Bitbucket users. The free tier is significantly weaker at 50 minutes per month. The ecosystem of reusable pipes is smaller. The feature set is more limited. Unless your team is deeply embedded in the Atlassian ecosystem, Bitbucket Pipelines rarely competes with Actions on merit.

9. Use Cases: Where GitHub Actions Excels

\[VISUAL: Use case grid showing different team types with their typical workflow configurations\]

Open Source Project Maintenance: Unlimited free minutes, automatic PR checks, community contributor CI, and release automation make Actions the default choice. We run PR validation, automated changelog generation, and npm publishing through Actions workflows with zero cost.

Full-Stack Web Application CI/CD: Frontend builds, API testing, database migrations, Docker image building, and multi-environment deployments all chain together naturally. Matrix builds validate across Node versions while deployment workflows target staging and production with approval gates.

Infrastructure as Code: Terraform plan on PR, apply on merge. GitHub Actions' environment protection rules map perfectly to infrastructure deployment approvals. Our Terraform workflows include cost estimation, drift detection, and automated documentation generation.

Monorepo Management: Path filters trigger workflows only when relevant directories change. A monorepo with frontend and backend directories can run separate CI pipelines for each, only executing when files in that directory are modified. This saves significant compute minutes compared to running everything on every push.

Scheduled Maintenance Tasks: Cron-triggered workflows handle dependency updates, security scans, data backups, and reporting. We run nightly security scans, weekly dependency update PRs via Dependabot integration, and monthly infrastructure audits as scheduled Actions workflows.

10. Who Should NOT Use GitHub Actions

Teams not on GitHub. This sounds obvious but deserves stating. If your code lives on GitLab, Bitbucket, or a self-hosted Git server, GitHub Actions provides zero value without a platform migration. Do not move your repositories just for CI/CD.

iOS/macOS-heavy development teams on a budget. The 10x cost multiplier for macOS runners makes Actions prohibitively expensive for teams running frequent, long macOS builds. A team of 10 iOS developers will almost certainly save money with self-hosted Mac Minis or a platform with better macOS pricing.

Teams needing advanced pipeline visualization. If your deployment pipeline involves complex dependencies, conditional branching, and multi-stage approvals that stakeholders need to visualize and understand, GitLab CI or specialized deployment platforms like Octopus Deploy offer far better visual tooling.

Organizations requiring air-gapped environments. While GitHub Enterprise Server supports Actions, the experience is degraded without marketplace access. Organizations with strict air-gap requirements may find Jenkins or GitLab's self-managed offering more practical.

11. Security & Compliance

\[VISUAL: Security architecture diagram showing secrets management, runner isolation, and permission boundaries\]

GitHub Actions takes security seriously, but the responsibility model requires attention. Secrets are encrypted at rest and masked in logs, but careless workflow configurations can still leak them. The `GITHUB_TOKEN` automatically provisioned for each workflow run follows the principle of least privilege, scoped to the triggering repository with configurable permissions.

12. Support Channels & Resources

GitHub's documentation for Actions is comprehensive and well-maintained. The official docs cover workflow syntax, security hardening, migration guides, and practical examples. This is one area where GitHub genuinely excels compared to competitors.

Community support through GitHub Discussions, Stack Overflow, and the GitHub Community Forum fills gaps where official documentation falls short. Most workflow errors have existing solutions online due to the platform's massive adoption. I have never spent more than 30 minutes searching for a solution to a common Actions problem.

13. Performance & Reliability

\[VISUAL: Performance benchmark chart showing runner startup times and build speeds across runner types\]

GitHub Actions performance depends heavily on runner selection and workflow optimization. Hosted runner startup times range from 15-45 seconds, adding overhead to every job. Self-hosted runners start near-instantly since they are already running.

Build speeds on standard Linux runners (2-core, 7GB RAM) are adequate for most workloads but not exceptional. Our Next.js frontend build takes 4 minutes on a standard runner versus 90 seconds on our self-hosted 8-core machine. Larger hosted runners (available on Team and Enterprise plans) close this gap but at higher cost.

Caching is critical for performance. Actions provides 10GB of cache per repository using the `actions/cache` action. Properly caching `node_modules`, Python virtual environments, and Docker layers cuts our average workflow duration by 60%. Without caching, every run reinstalls dependencies from scratch.

Reliability has been generally strong. GitHub's status page shows Actions availability consistently above 99.9%. We have experienced two notable outages in eighteen months, both resolved within two hours. Compared to our Jenkins server, which required manual intervention monthly, the hosted reliability is a significant improvement.

14. Final Verdict: Is GitHub Actions Worth It?

\[VISUAL: Final scorecard graphic with ratings across all evaluation dimensions\]

GitHub Actions earns a solid 8.2 out of 10 for teams already working on GitHub. The native integration eliminates friction that standalone CI/CD tools introduce, the marketplace ecosystem accelerates workflow development, and the pricing model is competitive for Linux-based workloads.

The platform falls short on debugging experience, macOS pricing, and advanced pipeline visualization. Teams with complex deployment requirements or heavy Apple platform development should evaluate alternatives carefully.

ROI Analysis

For a team of 10 developers on the Team plan ($4/user/month), the total GitHub cost increase for Actions is $40/month plus any overage minutes. Compare this to CircleCI's Performance plan at $15/user/month ($150/month) or the operational cost of maintaining a Jenkins server (conservatively $500-1,000/month in engineer time).

The ROI math strongly favors Actions for GitHub-native teams. We estimate our migration from Jenkins saved approximately $12,000 annually in direct costs and engineering time. The only scenario where Actions loses on ROI is heavy macOS usage where self-hosted runners or alternative platforms become more economical.

Bottom Line: If your code is on GitHub, start with GitHub Actions. You will be productive within a day, and the integrated experience is worth more than any feature advantage a standalone CI/CD tool might offer. Only look elsewhere if you hit specific pain points around macOS costs, debugging needs, or advanced deployment orchestration.

Is GitHub Actions really free for open source projects?

Yes, completely. Public repositories get unlimited minutes on Linux, Windows, and macOS runners with no feature restrictions. This applies to all GitHub plans, including Free. There is no catch, no time limit, and no degraded feature set. This policy has made Actions the standard CI/CD platform for open source development.

How do GitHub Actions minutes work across different runner types?

Linux minutes are counted at 1x rate. Windows minutes count at 2x, meaning a 10-minute Windows job consumes 20 minutes from your quota. macOS counts at 10x, so that same 10-minute job would consume 100 minutes. Self-hosted runners consume zero included minutes regardless of operating system.

Can I use GitHub Actions with repositories hosted outside of GitHub?

No. GitHub Actions only works with repositories hosted on GitHub.com or GitHub Enterprise. If your code is on GitLab, Bitbucket, or a self-hosted Git server, you cannot use Actions without migrating your repository to GitHub. Some teams mirror repositories to GitHub specifically for Actions, but this adds complexity.

How do I keep my secrets safe in GitHub Actions?

Use GitHub's encrypted secrets feature, which encrypts values at rest and masks them in workflow logs. Prefer OIDC authentication over stored credentials for cloud providers. Never echo secrets in workflow steps. Restrict secret access to specific environments. Avoid granting secret access to workflows triggered by fork pull requests. Regularly rotate secrets and audit access.

What happens when I exceed my included minutes?

GitHub charges per-minute overages to the payment method on the organization or account. There is no hard cutoff - workflows continue running, and you are billed at the end of the billing cycle. You can set spending limits (including $0) to prevent unexpected charges. We recommend setting a spending limit slightly above your expected usage to catch anomalies early.

Can GitHub Actions replace my entire deployment pipeline?

For most web applications, yes. Actions handles building, testing, creating artifacts, deploying to cloud providers, running database migrations, and sending notifications. For complex enterprise deployments with sophisticated rollback strategies, canary deployments, or multi-region orchestration, you may want a specialized deployment tool like ArgoCD or Spinnaker working alongside Actions.

How does GitHub Actions compare to GitHub's older CI solution, Travis CI integration?

Travis CI was a separate third-party service that integrated with GitHub via webhooks. GitHub Actions is native to the platform with deeper integration, better performance, and a larger ecosystem. Travis CI experienced reliability issues and a controversial pricing change in 2020 that drove most projects to migrate to Actions. There is virtually no reason to choose Travis CI over Actions today.

Are self-hosted runners worth the operational overhead?

It depends on your usage. If you spend more than $200/month on hosted runner overages, self-hosted runners likely save money. If you need GPU access, specialized hardware, or private network connectivity, self-hosted runners are necessary. For teams spending under $100/month on Actions with standard compute needs, the operational overhead of maintaining runners is not justified.

Can I run Docker containers in GitHub Actions workflows?

Yes, and it works well. You can use container jobs to run entire jobs inside a Docker container, use service containers for dependencies like databases and caches, and build and push Docker images as workflow steps. Linux runners support Docker natively. Windows runners have limited Docker support. macOS runners do not support Docker containers.

How do I migrate from Jenkins to GitHub Actions?

Start by inventorying your Jenkins pipelines and categorizing them by complexity. Migrate simple pipelines first to build confidence. Replace Jenkins plugins with marketplace actions. Convert Groovy pipeline syntax to YAML workflow definitions. Migrate credentials to GitHub secrets. Run both systems in parallel during transition. Budget 2-4 weeks for a team with 5-10 pipelines.

What is the maximum workflow run time?

Individual jobs can run for up to 6 hours on hosted runners. A complete workflow can run for up to 35 days (though this would be extraordinarily unusual and expensive). Self-hosted runner jobs have no time limit by default, though you can configure timeouts. We recommend setting explicit `timeout-minutes` on every job to prevent runaway builds from consuming your minutes.

Does GitHub Actions support monorepos effectively?

Yes, through path filters on triggers. You can configure workflows to only run when files in specific directories change, preventing unnecessary builds for unaffected services. Combined with reusable workflows, monorepo CI/CD on Actions is practical and efficient for repositories with up to 20-30 services. Beyond that scale, build tools like Nx or Turborepo add intelligent caching that complements Actions well.