ELI5: Why does our CI bill go up even when code commits are down?

Our devs merged 50% less code last month, but the CI platform invoice was 15% higher. Makes no sense.

The usual suspects:
* **Longer pipelines.** New security scans, integration tests, or "deploy to staging" steps tacked on.
* **Larger runners.** Someone moved from 2 vCPU to 4 vCPU "because builds felt slow."
* **Idle minutes.** Scheduled pipelines (nightly, hourly) running regardless of commit activity.
* **Caching inefficiency.** Dependency caches getting invalidated or not shared between parallel jobs.

Check your build duration trend, not just count. Also, look for any new services (like SaaS security tools) added to the workflow that bill per minute of runtime.