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How to control matrix explosion

A small matrix change tripled the job count and the bill.

4 min read

A small matrix change tripled the job count and the bill.

Why it happens

Adding one dimension multiplies rather than adds.

How to fix it

  1. Test the full product nightly and a representative subset on pull requests
  2. Use include for the specific combinations that matter
  3. Alert on job count per workflow so growth is visible

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