What CI/CD systems have you used in your work?

In my work, I used the following CI/CD systems:

• Jenkins — a flexible and extensible automation server that allows building complex pipelines.
• GitLab CI/CD — an integrated system within GitLab with convenient pipeline descriptions via .gitlab-ci.yml.
• TeamCity — a powerful tool with a user-friendly UI and support for many technologies.
• CircleCI — a cloud solution with quick startup and scalability.

Each system allows automating the build, testing, and deployment of applications, integrates with version control systems and monitoring tools.