What is the minimum number of instances required for stable CI/CD process implementation?

For the stable implementation of CI/CD processes (continuous integration and delivery), at least two instances are minimally required:

1. Build server (CI server) — responsible for automatic building, testing, and verification of code with each change.
2. Deployment environment (CD server or staging/production server) — the place where the built and tested versions of the application are automatically deployed.

In the simplest case, these roles can be combined on one server, but for reliability and scalability, it is better to separate them.

It is also common to add:

• Code repository (e.g., Git)
• Artifact management system

Thus, the minimum number is 2, but depending on the complexity of the project and infrastructure requirements, it can be more.