diff --git a/.github/workflows/runtime_test.yml b/.github/workflows/runtime_test.yml
index 118a520ad59c9..90ead473611ce 100644
--- a/.github/workflows/runtime_test.yml
+++ b/.github/workflows/runtime_test.yml
@@ -7,66 +7,38 @@ on:
     paths-ignore:
       - 'compiler/**'
 
-env:
-  # Number of workers (one per shard) to spawn
-  SHARD_COUNT: 5
-
 jobs:
-  # Define the various test parameters and parallelism for this workflow
-  build_test_params:
-    name: Build test params
-    runs-on: ubuntu-latest
-    outputs:
-      params: ${{ steps.define-params.outputs.result }}
-      shard_id: ${{ steps.define-shards.outputs.result }}
-    steps:
-      - uses: actions/github-script@v7
-        id: define-shards
-        with:
-          script: |
-            function range(from, to) {
-              const arr = [];
-              for (let n = from; n <= to; n++) {
-                arr.push(n);
-              }
-              return arr;
-            }
-            return range(1, process.env.SHARD_COUNT);
-      - uses: actions/github-script@v7
-        id: define-params
-        with:
-          script: |
-            return [
-              "-r=stable --env=development",
-              "-r=stable --env=production",
-              "-r=experimental --env=development",
-              "-r=experimental --env=production",
-              "-r=www-classic --env=development --variant=false",
-              "-r=www-classic --env=production --variant=false",
-              "-r=www-classic --env=development --variant=true",
-              "-r=www-classic --env=production --variant=true",
-              "-r=www-modern --env=development --variant=false",
-              "-r=www-modern --env=production --variant=false",
-              "-r=www-modern --env=development --variant=true",
-              "-r=www-modern --env=production --variant=true",
-              "-r=xplat --env=development --variant=false",
-              "-r=xplat --env=development --variant=true",
-              "-r=xplat --env=production --variant=false",
-              "-r=xplat --env=production --variant=true",
-              // TODO: Test more persistent configurations?
-              "-r=stable --env=development --persistent",
-              "-r=experimental --env=development --persistent"
-            ];
-
-  # Spawn a job for each shard for a given set of test params
   test:
-    name: yarn test ${{ matrix.params }} (Shard ${{ matrix.shard_id }})
+    name: yarn test ${{ matrix.params }} (Shard ${{ matrix.shard }})
     runs-on: ubuntu-latest
-    needs: build_test_params
     strategy:
       matrix:
-        params: ${{ fromJSON(needs.build_test_params.outputs.params) }}
-        shard_id: ${{ fromJSON(needs.build_test_params.outputs.shard_id) }}
+        params:
+          - "-r=stable --env=development"
+          - "-r=stable --env=production"
+          - "-r=experimental --env=development"
+          - "-r=experimental --env=production"
+          - "-r=www-classic --env=development --variant=false"
+          - "-r=www-classic --env=production --variant=false"
+          - "-r=www-classic --env=development --variant=true"
+          - "-r=www-classic --env=production --variant=true"
+          - "-r=www-modern --env=development --variant=false"
+          - "-r=www-modern --env=production --variant=false"
+          - "-r=www-modern --env=development --variant=true"
+          - "-r=www-modern --env=production --variant=true"
+          - "-r=xplat --env=development --variant=false"
+          - "-r=xplat --env=development --variant=true"
+          - "-r=xplat --env=production --variant=false"
+          - "-r=xplat --env=production --variant=true"
+          # TODO: Test more persistent configurations?
+          - "-r=stable --env=development --persistent"
+          - "-r=experimental --env=development --persistent"
+        shard:
+          - 1/5
+          - 2/5
+          - 3/5
+          - 4/5
+          - 5/5
     continue-on-error: true
     steps:
       - uses: actions/checkout@v4
@@ -82,4 +54,4 @@ jobs:
           path: "**/node_modules"
           key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
       - run: yarn install --frozen-lockfile
-      - run: yarn test ${{ matrix.params }} --ci=github --shard=${{ matrix.shard_id }}/${{ env.SHARD_COUNT }}
+      - run: yarn test ${{ matrix.params }} --ci=github --shard=${{ matrix.shard }}