fil/.github/documentation/runners.md

Custom GitHub Actions Runners

Available Runners

Runner Label	Architecture	Size	Ephemeral	Notes
runner-small	x86_64	Small	No	Light tasks: linting, formatting, validation
runner-medium	x86_64	Medium	No	Standard CI: tests, builds
runner-medium-arm64	arm64	Medium	No	ARM64 builds and tests
runner-large	x86_64	Large	No	Heavy workloads: benchmarks, coverage, release builds
runner-large-spot	x86_64	Large	Yes	Cost-optimized large jobs where interruption is acceptable
runner-medium-arm64-spot	arm64	Medium	Yes	Cost-optimized ARM64 jobs where interruption is acceptable

Spot Runners

Spot runners (*-spot) use ephemeral cloud instances provisioned on a best-effort basis. They are significantly cheaper but can be preempted at any time if the cloud provider reclaims capacity.

Use spot runners for:

• Jobs that can be retried without consequence (test suites, linting)
• Non-time-critical workloads
• PR validation where re-runs are acceptable

Do not use spot runners for:

• Benchmarks (preemption and noisy-neighbor effects skew results)
• Release builds and publishing
• Jobs requiring consistent, reproducible timing

Choosing a Runner

Workload	Recommended Runner
Linting, formatting, validation	runner-small
Unit tests, standard builds	runner-medium
ARM64 cross-compilation / tests	runner-medium-arm64
Benchmarks, coverage reports	runner-large
Non-critical large builds	runner-large-spot
Non-critical ARM64 builds	runner-medium-arm64-spot