Migrate from Blacksmith to runnerhut

What Blacksmith does well

• Strong engineering brand — genuinely good writing on Docker caching and CI economics
• Gaming-grade bare-metal CPUs for single-threaded build speed
• SOC 2 Type 2, plus a Tailscale integration for private network access
• Well-known logos and a mature customer-story programme

Where we differ

• No comparison, glossary or solution pages — thin coverage for teams researching options
• No bring-your-own-cloud option: builds run on their infrastructure or not at all
• Fewer published runner families than platforms offering Windows and GPU tiers

The migration

jobs:
  build:
-   runs-on: blacksmith-4vcpu-ubuntu-2204
+   runs-on: runnerhut-8vcpu-ubuntu-2404
    steps:
      - uses: actions/checkout@v4

And the migration back

We publish this because after BuildJet's shutdown, "what if you disappear" is a fair question. Leaving is the same single line you changed to arrive.

jobs:
  build:
-   runs-on: runnerhut-8vcpu-ubuntu-2404
+   runs-on: ubuntu-latest

Checklist

1. Install the runnerhut GitHub App on the repositories you want to move
2. Change runs-on in one job first and compare timings against the old runner
3. Add runner.arch to cache keys if you are also moving to arm64
4. Roll out to the rest of the repository once the comparison looks right
5. Set a budget cap and concurrency cancellation before going organisation-wide