How did you set up the CI/CD pipeline in GitLab?

To set up a CI/CD pipeline in GitLab, I created a .gitlab-ci.yml file in the root of the repository, where I described the stages and jobs. For example:

stages:
  - build
  - test
  - deploy

build_job:
  stage: build
  script:
    - echo "Building project..."
    - python setup.py install

test_job:
  stage: test
  script:
    - pytest tests/

deploy_job:
  stage: deploy
  script:
    - echo "Deploying to production..."
  only:
    - main

In this file, I defined the sequence of stages, commands to execute, and conditions for running (for example, deploying only from the main branch). I also configured runners for executing tasks and integrated with external services (such as Docker Registry or Kubernetes) for automatic deployment.