diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
index b38e2af..360930d 100644
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -71,6 +71,47 @@ jobs:
           service_account: ${{ vars.TERRAFORM_SERVICE_ACCOUNT }}
 
       - uses: google-github-actions/setup-gcloud@v2
+      - name: Preserve existing Cloud Run ingress mode
+        id: ingress
+        shell: bash
+        run: |
+          set -euo pipefail
+          ingress_values=()
+          for service in api web; do
+            if ! ingress="$(gcloud run services describe "${{ steps.config.outputs.resource_name }}-$service" \
+              --project "${{ steps.config.outputs.project_id }}" \
+              --region "${{ steps.config.outputs.region }}" \
+              --format="value(metadata.annotations.'run.googleapis.com/ingress')" 2>&1)"; then
+              if [[ "$ingress" == *"NOT_FOUND"* ]]; then
+                continue
+              fi
+              printf '%s\n' "$ingress" >&2
+              exit 1
+            fi
+            test -n "$ingress"
+            if [ -n "$ingress" ]; then
+              ingress_values+=("$ingress")
+            fi
+          done
+
+          public_ingress=true
+          if [ "${#ingress_values[@]}" -gt 0 ]; then
+            for ingress in "${ingress_values[@]}"; do
+              case "$ingress" in
+                all) ;;
+                internal-and-cloud-load-balancing) public_ingress=false ;;
+                *) echo "Unsupported Cloud Run ingress value: $ingress" >&2; exit 1 ;;
+              esac
+            done
+          fi
+
+          if [ "$public_ingress" = false ]; then
+            for ingress in "${ingress_values[@]}"; do
+              test "$ingress" = "internal-and-cloud-load-balancing"
+            done
+          fi
+
+          echo "public_ingress=$public_ingress" >> "$GITHUB_OUTPUT"
       - name: Resolve private ClickHouse MCP endpoint
         id: mcp
         shell: bash
@@ -109,7 +150,8 @@ jobs:
             -var="service=api" \
             -var="api_image=${{ steps.config.outputs.registry }}/api:${{ steps.config.outputs.sha }}" \
             -var="web_image=unused" \
-            -var="mcp_endpoint=${{ steps.mcp.outputs.uri }}"
+            -var="mcp_endpoint=${{ steps.mcp.outputs.uri }}" \
+            -var="public_ingress=${{ steps.ingress.outputs.public_ingress }}"
 
       - name: Resolve deployed API URL
         if: steps.config.outputs.component == 'web' || steps.config.outputs.component == 'all'
@@ -149,4 +191,5 @@ jobs:
             -var="service=web" \
             -var="api_image=unused" \
             -var="web_image=${{ steps.config.outputs.registry }}/web:${{ steps.config.outputs.sha }}" \
-            -var="api_base_url=${{ steps.api.outputs.uri }}"
+            -var="api_base_url=${{ steps.api.outputs.uri }}" \
+            -var="public_ingress=${{ steps.ingress.outputs.public_ingress }}"
diff --git a/.github/workflows/public-domain-control.yml b/.github/workflows/public-domain-control.yml
index 359afe8..a0ee140 100644
--- a/.github/workflows/public-domain-control.yml
+++ b/.github/workflows/public-domain-control.yml
@@ -21,7 +21,7 @@ on:
         required: false
 
 concurrency:
-  group: public-domain-control-sandbox
+  group: deploy-sandbox
   cancel-in-progress: false
 
 jobs:
diff --git a/infra/terraform/tools/config-validator/test/public-edge-assets.test.mjs b/infra/terraform/tools/config-validator/test/public-edge-assets.test.mjs
index f44ecfc..aec150b 100644
--- a/infra/terraform/tools/config-validator/test/public-edge-assets.test.mjs
+++ b/infra/terraform/tools/config-validator/test/public-edge-assets.test.mjs
@@ -35,3 +35,17 @@ test("lockdown reads the deployed Cloud Run images instead of absent Terraform s
   assert.match(workflow, /test -n "\$mcp_endpoint"/);
   assert.doesNotMatch(workflow, /terraform -chdir=infra\/terraform\/components\/app output -raw (?:api_image|web_image)/);
 });
+
+test("deployment serializes with lockdown and preserves the existing ingress mode", () => {
+  const deploy = readFileSync(new URL(".github/workflows/deploy.yml", repositoryRoot), "utf8");
+  const publicDomain = readFileSync(new URL(".github/workflows/public-domain-control.yml", repositoryRoot), "utf8");
+
+  assert.match(deploy, /concurrency:\n  group: deploy-sandbox/);
+  assert.match(publicDomain, /concurrency:\n  group: deploy-sandbox/);
+  assert.match(deploy, /id: ingress/);
+  assert.match(deploy, /for service in api web; do/);
+  assert.match(deploy, /gcloud run services describe "\$\{\{ steps\.config\.outputs\.resource_name \}\}-\$service"/);
+  assert.match(deploy, /NOT_FOUND/);
+  assert.doesNotMatch(deploy, /2>\/dev\/null \|\| true/);
+  assert.match(deploy, /-var="public_ingress=\$\{\{ steps\.ingress\.outputs\.public_ingress \}\}"/);
+});