What is CI/CD and how does it work?

CI/CD stands for Continuous Integration and Continuous Delivery/Deployment.

**Continuous Integration (CI):**
- Developers push code frequently (multiple times per day)
- Automated tests run on every push
- Build is created and verified
- Catches bugs early before they compound

**Continuous Delivery (CD):**
- After CI passes, code is automatically prepared for release
- One-click deployment to production

**Continuous Deployment:**
- Goes further — automatically deploys to production without human approval

**Typical CI/CD pipeline:**
```
Code Push → Build → Unit Tests → Integration Tests → Staging Deploy → Smoke Tests → Production Deploy
```

**Popular tools:**
- GitHub Actions, Jenkins, GitLab CI (pipeline orchestration)
- Docker (consistent build environments)
- Kubernetes (production deployment)

Companies using CI/CD deploy 10-100x more frequently with fewer bugs.