GitLab Runner: Running jobs in parallel

This documentation is part of the Building Docker images guide. View the full guide here: Build and push Docker images from your GitLab CI/CD pipelines using your Stackhero runner and Docker-in-Docker.

👋 Welcome to the Stackhero documentation!

Stackhero gives you an easy-to-use GitLab Runner cloud solution designed to handle your GitLab CI/CD jobs efficiently. Here is what you can look forward to:

• Unlimited CI/CD minutes: there is no per-minute billing, so your pipelines can run whenever you need them.
• Multiple concurrent jobs: run several jobs at the same time to speed up your entire pipeline.
• The Docker executor with Docker-in-Docker support: streamline building and pushing your container images.
• Compatible with GitLab.com as well as any self-managed GitLab instance.
• A private, dedicated VM powered by fast NVMe/SSD disks for consistent, reliable builds.
• Available in both 🇪🇺 Europe and 🇺🇸 USA regions.

Save time: you can connect your first GitLab Runner and start running pipelines in just a few minutes!

Your plan controls how many jobs can run at the same time. Jobs within the same stage will start together, up to your concurrency limit. This means a stage with multiple independent jobs can finish as soon as the slowest job completes, rather than running all jobs sequentially.

Here is a simple example:

stages:
  - test

unit:
  stage: test
  image: node:22
  script: npm run test:unit

integration:
  stage: test
  image: node:22
  script: npm run test:integration

e2e:
  stage: test
  image: node:22
  script: npm run test:e2e

If you set your concurrency to 3 or higher, the unit, integration, and e2e jobs will all run at the same time.

If you would like more in-depth information about building Docker images in CI, feel free to check out the official GitLab documentation.