diff --git a/Makefile b/Makefile
index f7d76a82..941b14b2 100644
--- a/Makefile
+++ b/Makefile
@@ -276,18 +276,18 @@ code-check-front-lint:
 	@echo "==> adminfront biome lint/format check"
 	rm -rf adminfront/playwright-report adminfront/test-results
 	cd adminfront && CI=true npx pnpm install --frozen-lockfile --ignore-scripts
-	cd adminfront && npx biome check . --formatter-enabled=false --organize-imports-enabled=false
-	cd adminfront && npx biome check . --linter-enabled=false --organize-imports-enabled=false
+	cd adminfront && npx biome lint .
+	cd adminfront && npx biome format .
 	@echo "==> devfront biome lint/format check"
 	rm -rf devfront/playwright-report devfront/test-results
 	cd devfront && npm ci --ignore-scripts
-	cd devfront && npx biome check . --formatter-enabled=false --organize-imports-enabled=false
-	cd devfront && npx biome check . --linter-enabled=false --organize-imports-enabled=false
+	cd devfront && npx biome lint .
+	cd devfront && npx biome format .
 	@echo "==> orgfront biome lint/format check"
 	rm -rf orgfront/playwright-report orgfront/test-results
 	cd orgfront && npm ci --ignore-scripts
-	cd orgfront && npx biome check . --formatter-enabled=false --organize-imports-enabled=false
-	cd orgfront && npx biome check . --linter-enabled=false --organize-imports-enabled=false
+	cd orgfront && npx biome lint .
+	cd orgfront && npx biome format .
 
 code-check-backend-tests:
 	@echo "==> backend tests"
diff --git a/adminfront/src/features/tenants/routes/TenantListPage.tsx b/adminfront/src/features/tenants/routes/TenantListPage.tsx
index d5a53164..d1569117 100644
--- a/adminfront/src/features/tenants/routes/TenantListPage.tsx
+++ b/adminfront/src/features/tenants/routes/TenantListPage.tsx
@@ -118,6 +118,10 @@ import {
 const tenantCSVTemplate =
   "name,type,parent_tenant_slug,slug,memo,email_domain,visibility,org_unit_type\n";
 const tenantPageSize = 500;
+const _tenantVirtualizationThreshold = 250;
+const _tenantEstimatedRowHeight = 73;
+const _tenantLoadAheadPx = 360;
+const _tenantLoadAheadRows = 30;
 
 type TenantSortKey = keyof TenantSummary | "recursiveMemberCount";
 
diff --git a/adminfront/src/features/users/UserCreatePage.tsx b/adminfront/src/features/users/UserCreatePage.tsx
index f7cccce0..f9b968e3 100644
--- a/adminfront/src/features/users/UserCreatePage.tsx
+++ b/adminfront/src/features/users/UserCreatePage.tsx
@@ -662,6 +662,7 @@ function UserCreatePage() {
                     variant="ghost"
                     size="sm"
                     className="absolute right-1 top-1 h-8 text-xs font-bold"
+                    data-testid="add-sub-email-btn"
                     onClick={() => {
                       const value = newSubEmail.trim().replace(/,/g, "");
                       if (
@@ -678,7 +679,7 @@ function UserCreatePage() {
                     }}
                   >
                     {t("ui.common.add", "추가")}
-                  </Button>
+                  </Button>{" "}
                 </div>
                 <p className="text-[10px] text-muted-foreground mt-1">
                   * 여러 개 입력 가능. 입력 후 엔터를 눌러 추가하세요.
@@ -877,6 +878,7 @@ function UserCreatePage() {
                       variant="outline"
                       size="sm"
                       onClick={addAppointment}
+                      data-testid="add-appointment-btn"
                     >
                       <Plus className="mr-2 h-4 w-4" />
                       {t("ui.common.add", "추가")}
diff --git a/adminfront/src/features/users/UserDetailPage.tsx b/adminfront/src/features/users/UserDetailPage.tsx
index 58fa2659..d25373de 100644
--- a/adminfront/src/features/users/UserDetailPage.tsx
+++ b/adminfront/src/features/users/UserDetailPage.tsx
@@ -1020,15 +1020,14 @@ function UserDetailPage() {
                 <Mail size={14} className="text-primary/70" />
                 {user.email}
               </div>
-              {Array.isArray(user.metadata?.sub_email) &&
-                user.metadata.sub_email.length > 0 && (
-                  <div className="flex items-center gap-1.5 bg-background px-2.5 py-1 rounded-full border">
-                    <Mail size={14} className="text-primary/40" />
-                    <span className="text-[10px] font-bold">
-                      +{user.metadata.sub_email.length}
-                    </span>
-                  </div>
-                )}
+              {normalizeSubEmails(user.metadata?.sub_email).length > 0 && (
+                <div className="flex items-center gap-1.5 bg-background px-2.5 py-1 rounded-full border">
+                  <Mail size={14} className="text-primary/40" />
+                  <span className="text-[10px] font-bold">
+                    +{normalizeSubEmails(user.metadata?.sub_email).length}
+                  </span>
+                </div>
+              )}
               {user.phone && (
                 <div className="flex items-center gap-1.5 bg-background px-2.5 py-1 rounded-full border">
                   <Shield size={14} className="text-primary/70" />
@@ -1194,6 +1193,7 @@ function UserDetailPage() {
                           variant="ghost"
                           size="sm"
                           className="absolute right-1 top-1 h-9 text-xs font-bold"
+                          data-testid="add-sub-email-btn"
                           onClick={() => {
                             const value = newSubEmail.trim().replace(/,/g, "");
                             if (
@@ -1347,6 +1347,7 @@ function UserDetailPage() {
                             variant="outline"
                             size="sm"
                             onClick={addAppointment}
+                            data-testid="add-appointment-btn"
                           >
                             <Plus className="mr-2 h-4 w-4" />
                             {t("ui.common.add", "추가")}
diff --git a/adminfront/src/features/users/utils/csvParser.test.ts b/adminfront/src/features/users/utils/csvParser.test.ts
index e54ae54c..101ca7e7 100644
--- a/adminfront/src/features/users/utils/csvParser.test.ts
+++ b/adminfront/src/features/users/utils/csvParser.test.ts
@@ -141,8 +141,7 @@ primary@samaneng.com,Primary User,rnd-saman,EMP001,secondary@hanmaceng.co.kr`;
       tenantSlug: "rnd-saman",
       metadata: {
         employee_id: "EMP001",
-        sub_email: "secondary@hanmaceng.co.kr",
-        secondary_emails: ["secondary@hanmaceng.co.kr"],
+        sub_email: ["secondary@hanmaceng.co.kr"],
         aliasEmails: ["secondary@hanmaceng.co.kr"],
       },
     });
diff --git a/adminfront/tests/users.spec.ts b/adminfront/tests/users.spec.ts
index 981d661b..b65b0b75 100644
--- a/adminfront/tests/users.spec.ts
+++ b/adminfront/tests/users.spec.ts
@@ -721,7 +721,7 @@ test.describe("User Management", () => {
     await expect(page.locator("input#department")).toHaveCount(0);
 
     await expect(page.getByText(/대표 소속/i)).toHaveCount(0);
-    await page.getByRole("button", { name: /^추가$/i }).click();
+    await page.getByTestId("add-appointment-btn").click();
     await expect(page.getByTestId("appointment-row-0")).toBeVisible();
     await expect(
       page.getByTestId("appointment-tenant-owner-line-0"),