The 12 CI workflow anti-patterns burning your budget right now

PROBLEM

All workflows run on every push regardless of which files changed. A documentation edit triggers a 20-minute build and test suite.

FIX

on:
  push:
    paths:
      - 'src/**'
      - 'package.json'
      - '*.config.*'

PROBLEM

Developer pushes three commits in 90 seconds. Three identical builds run in parallel, two will be cancelled anyway when the next commit arrives.

FIX

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

See full guide →

PROBLEM

Cache keys that hash the entire repo, or no cache at all. Every build restores nothing and installs from scratch.

FIX

Use lockfile hash as the cache key. See dependency caching recipes. — see full guide

PROBLEM

30-minute test suite runs on every commit to every branch. 80% of tests are unrelated to the changed files.

FIX

Add paths filter to test workflow. Adopt affected-only logic (Nx, Turborepo, Bazel) for monorepos. — see full guide

PROBLEM

A runaway job, hung integration test, or deadlocked build process consumes hours of billed minutes before the developer notices.

FIX

jobs:
  build:
    timeout-minutes: 20
    steps:
      - timeout-minutes: 10
        run: npm test

PROBLEM

Team uses macos-latest as the default from a StackOverflow answer. Their Node.js backend has zero Apple-specific code. They are paying 10x Linux rate.

FIX

Change runs-on: macos-latest to runs-on: ubuntu-latest for any non-macOS-specific workflow.

PROBLEM

Playwright or Cypress E2E suite runs on every commit. E2E tests are slow (15-60 min), flaky, and often redundant on feature branches.

FIX

Move E2E to nightly schedule + pre-merge trigger only, or scope with paths filter to UI-related changes. — see full guide

PROBLEM

Using runs-on: ubuntu-latest-16-core for a 2-core workload. 16-core runners cost 8x more than 2-core. The build time is not 8x faster.

FIX

Profile actual CPU utilisation during your build. Right-size to the largest runner where utilisation exceeds 70%.

PROBLEM

Docker image rebuilds from scratch on every run. No cache-from configuration. 8-minute Docker build on every PR.

FIX

Add cache-from: type=gha and cache-to: type=gha,mode=max to docker/build-push-action. — see full guide

PROBLEM

500 MB production build artifact uploaded on every PR. It is never downloaded. It eats the 500 MB free storage allowance in one run.

FIX

Filter artifacts: only upload on main/release branches. Set retention-days: 1 for PR artifacts.

PROBLEM

Caches and artifacts accumulate. GitHub evicts caches by LRU when the 10 GB cap is hit, but artifacts require explicit retention policies.

FIX

Set retention-days on all artifact uploads. Add a weekly cleanup workflow using actions/cache delete.

PROBLEM

A popular action downloads a 200 MB CLI tool on every run. Multiply by 100 PRs/day: 20 GB of unnecessary downloads.

FIX

Audit action sizes with workflow timing data. Replace heavyweight actions with direct CLI calls or first-party actions where possible.