diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f9b35ab..ce9cc58 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -22,7 +22,7 @@ concurrency:
 jobs:
   check:
     name: cargo check
-    runs-on: ubuntu-22.04
+    runs-on: blacksmith-4vcpu-ubuntu-2204
     steps:
       - name: Checkout
         uses: actions/checkout@v4
diff --git a/.github/workflows/publish-vscode-extension.yml b/.github/workflows/publish-vscode-extension.yml
index 6e953c3..866d26c 100644
--- a/.github/workflows/publish-vscode-extension.yml
+++ b/.github/workflows/publish-vscode-extension.yml
@@ -22,7 +22,7 @@ permissions:
 
 jobs:
   publish:
-    runs-on: ubuntu-latest
+    runs-on: blacksmith-4vcpu-ubuntu-2404
     # Map the optional Marketplace secret to an env var: the `secrets` context is
     # NOT allowed in a step `if:` (doing so makes the whole workflow invalid and
     # every run a startup failure), but the `env` context is.
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index f8ac286..b172115 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -48,35 +48,35 @@ jobs:
       matrix:
         include:
           - asset: autter-macos-arm64
-            os: macos-14
+            os: blacksmith-6vcpu-macos-15
             target: aarch64-apple-darwin
             tool: cargo
           - asset: autter-macos-x64
             # Cross-compile x86_64 on an Apple Silicon runner: the macOS SDK is
             # universal, and the scarce/deprecated macos-13 Intel runners can
             # leave this job queued for hours before it is cancelled.
-            os: macos-14
+            os: blacksmith-6vcpu-macos-15
             target: x86_64-apple-darwin
             tool: cargo
           - asset: autter-linux-x64
             # 22.04 keeps the glibc requirement low (2.35) for broader portability
-            os: ubuntu-22.04
+            os: blacksmith-4vcpu-ubuntu-2204
             target: x86_64-unknown-linux-gnu
             tool: cargo
           - asset: autter-linux-arm64
-            os: ubuntu-22.04
+            os: blacksmith-4vcpu-ubuntu-2204
             target: aarch64-unknown-linux-gnu
             tool: cross
           - asset: autter-windows-x64.exe
             # No OpenSSL needed on Windows: TLS goes through native-tls/SChannel,
             # and the only C build is the bundled SQLite (handled by cc + MSVC).
-            os: windows-2022
+            os: blacksmith-4vcpu-windows-2025
             target: x86_64-pc-windows-msvc
             tool: cargo
           - asset: autter-windows-arm64.exe
             # Cross-compile ARM64 on the x64 runner: the preinstalled VS 2022
             # toolchain includes the ARM64 MSVC compiler and libraries.
-            os: windows-2022
+            os: blacksmith-4vcpu-windows-2025
             target: aarch64-pc-windows-msvc
             tool: cargo
     steps:
@@ -130,7 +130,7 @@ jobs:
   release:
     name: Publish release
     needs: build
-    runs-on: ubuntu-latest
+    runs-on: blacksmith-4vcpu-ubuntu-2404
     # Only publish for tag pushes; workflow_dispatch runs stop after building.
     if: startsWith(github.ref, 'refs/tags/v')
     steps:
@@ -200,7 +200,7 @@ jobs:
   publish-npm:
     name: Publish npm package
     needs: release
-    runs-on: ubuntu-latest
+    runs-on: blacksmith-4vcpu-ubuntu-2404
     if: startsWith(github.ref, 'refs/tags/v')
     steps:
       - name: Checkout
diff --git a/.github/workflows/tag-release.yml b/.github/workflows/tag-release.yml
index 1cbe9e7..9a1e9f2 100644
--- a/.github/workflows/tag-release.yml
+++ b/.github/workflows/tag-release.yml
@@ -19,7 +19,7 @@ permissions:
 jobs:
   tag:
     name: Tag from Cargo.toml version
-    runs-on: ubuntu-latest
+    runs-on: blacksmith-4vcpu-ubuntu-2404
     steps:
       - name: Checkout
         uses: actions/checkout@v4