Building a CI/CD pipeline with GitLab CI streamlines software delivery by automating the steps from code commit to deployment. GitLab CI/CD is integrated directly with GitLab repositories, making setup easy for teams already using GitLab.

To begin, create a `.gitlab-ci.yml` file in your project’s root. This file outlines stages like *build*, *test*, and *deploy* and includes jobs for each. For example:

```yaml
stages:
  - build
  - test
  - deploy

build-job:
  stage: build
  script:
    - echo "Building..."
    - npm install
```

Each job is executed by a GitLab Runner, which can be hosted or self-managed. Pipelines are triggered by events like commits or merge requests, allowing for automated, continuous delivery and testing.

With GitLab CI/CD, teams automate repetitive tasks, improve release speed, and reduce errors, making the development process faster and more efficient.