Make Fabio Pitino (@fabiopitino) a backend maintainer

Overview

Trainee issue: #5655 (closed)

• Works at GitLab since April 2019.
  • started with devopsverify team
  • then into specific devopsverify ~"group::continuous integration" team
• Authored 116 merged MRs as of today
• I have expertise in CI/CD area.
• I have been trainee maintainer for 8 months.
• Many (but not all) of the reviews I've done as part of the maintainer training are in #5655 (closed). Some recent ones are missing.

Most relevant reviews

• Adapt Limitable for system-wide features
• Implement Shared Runner Minute Factors
• Implement allowing empty needs for jobs in DAG pipelines
• Expose attachment_url to TestCaseEntity
• Support passing CI variables via git push options
• Add logic to show buy ci minutes link

I'm opening this MR because I feel ready to be a backend maintainer. I would love your feedback that can help me understand what I should improve otherwise.

WDYT @gitlab-org/maintainers/rails-backend?