diff --git a/.gitignore b/.gitignore
index 9132568..9ac7740 100644
--- a/.gitignore
+++ b/.gitignore
@@ -50,3 +50,5 @@ yarn-error.log*
 
 test-results
 playwright-report
+
+/scripts/
\ No newline at end of file
diff --git a/__tests__/unit/components/SortDropdown.test.tsx b/__tests__/unit/components/SortDropdown.test.tsx
index 39db4e7..a4399cb 100644
--- a/__tests__/unit/components/SortDropdown.test.tsx
+++ b/__tests__/unit/components/SortDropdown.test.tsx
@@ -1,19 +1,21 @@
-import { describe, it, expect, vi } from 'vitest';
+import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { render, screen, fireEvent } from '@testing-library/react';
 import { SortDropdown } from '@/components/utils/SortDropdown';
 import { useSearchParams } from 'next/navigation';
-import { useRouter, usePathname } from 'next/navigation';
+import { useRouter, usePathname } from '@/i18n/routing';
 
 /* eslint-disable @typescript-eslint/no-explicit-any */
 
-// Mock next/navigation
+// Mock next/navigation for useSearchParams
 vi.mock('next/navigation', () => ({
-  useRouter: vi.fn(),
   useSearchParams: vi.fn(),
+}));
+
+// Mock @/i18n/routing
+vi.mock('@/i18n/routing', () => ({
+  useRouter: vi.fn(),
   usePathname: vi.fn(),
-  redirect: vi.fn(),
-  permanentRedirect: vi.fn(),
-  notFound: vi.fn(),
+  Link: ({ children, href, ...props }: any) => <a href={href} {...props}>{children}</a>,
 }));
 
 // Mock next-intl
diff --git a/__tests__/unit/lib/posts.helper.test.ts b/__tests__/unit/lib/posts.helper.test.ts
index 830f890..b519e55 100644
--- a/__tests__/unit/lib/posts.helper.test.ts
+++ b/__tests__/unit/lib/posts.helper.test.ts
@@ -183,7 +183,7 @@ describe('posts.helper - API Response Parsing', () => {
       };
 
       const result = extractBlogPostFromPage(mockPage);
-      expect(result.language).toBe('ko');
+      expect(result.language).toBe('KR');
     });
 
     it('should handle missing translation relation', () => {
diff --git a/playwright.config.ts b/playwright.config.ts
index e2ac87a..4eab76a 100644
--- a/playwright.config.ts
+++ b/playwright.config.ts
@@ -8,13 +8,13 @@ export default defineConfig({
   workers: process.env.CI ? 1 : undefined,
   reporter: 'html',
   webServer: {
-    command: 'npm run dev -- -p 3001',
-    url: 'http://localhost:3001',
+    command: 'npm run dev -- -p 3000',
+    url: process.env.NEXT_PUBLIC_BASE_URL || 'http://localhost:3000',
     reuseExistingServer: !process.env.CI,
     timeout: 120 * 1000,
   },
   use: {
-    baseURL: 'http://localhost:3001',
+    baseURL: process.env.NEXT_PUBLIC_BASE_URL || 'http://localhost:3000',
     trace: 'on-first-retry',
   },
   projects: [
diff --git a/src/components/error-fallbacks/CommentErrorFallback.tsx b/src/components/error-fallbacks/CommentErrorFallback.tsx
index 185bc88..9a8abea 100644
--- a/src/components/error-fallbacks/CommentErrorFallback.tsx
+++ b/src/components/error-fallbacks/CommentErrorFallback.tsx
@@ -1,3 +1,5 @@
+'use client';
+
 export function CommentErrorFallback() {
   return (
     <div className="mt-16 pt-8 border-t border-neutral-200 dark:border-neutral-800">
diff --git a/src/components/error-fallbacks/PostErrorFallback.tsx b/src/components/error-fallbacks/PostErrorFallback.tsx
index 5bfe704..ade0e13 100644
--- a/src/components/error-fallbacks/PostErrorFallback.tsx
+++ b/src/components/error-fallbacks/PostErrorFallback.tsx
@@ -1,3 +1,5 @@
+'use client';
+
 import { Link } from "@/i18n/routing";
 
 export function PostErrorFallback() {
diff --git a/src/components/utils/ActiveFilters.tsx b/src/components/utils/ActiveFilters.tsx
index 88ee53f..dd484ce 100644
--- a/src/components/utils/ActiveFilters.tsx
+++ b/src/components/utils/ActiveFilters.tsx
@@ -1,6 +1,7 @@
 'use client';
 
-import { useRouter, useSearchParams, usePathname } from 'next/navigation';
+import { useSearchParams } from 'next/navigation';
+import { useRouter, usePathname } from '@/i18n/routing';
 import { useTranslations } from 'next-intl';
 import { X } from 'lucide-react';
 
diff --git a/src/components/utils/Sidebar.tsx b/src/components/utils/Sidebar.tsx
index d51a81d..bc32a50 100644
--- a/src/components/utils/Sidebar.tsx
+++ b/src/components/utils/Sidebar.tsx
@@ -1,6 +1,7 @@
 'use client';
 
-import { useRouter, useSearchParams, usePathname } from 'next/navigation';
+import { useSearchParams } from 'next/navigation';
+import { useRouter, usePathname } from '@/i18n/routing';
 import { useTranslations } from 'next-intl';
 import { cn } from "@/lib/utils";
 import { SortDropdown } from "./SortDropdown";
diff --git a/src/components/utils/SortDropdown.tsx b/src/components/utils/SortDropdown.tsx
index b12e99f..8dfecd1 100644
--- a/src/components/utils/SortDropdown.tsx
+++ b/src/components/utils/SortDropdown.tsx
@@ -1,6 +1,7 @@
 'use client';
 
-import { useRouter, useSearchParams, usePathname } from 'next/navigation';
+import { useSearchParams } from 'next/navigation';
+import { useRouter, usePathname } from '@/i18n/routing';
 import { useTranslations } from 'next-intl';
 import { SortOption } from '@/lib/types';
 
diff --git a/src/lib/services/posts.helper.ts b/src/lib/services/posts.helper.ts
index 9dc3840..7c46fee 100644
--- a/src/lib/services/posts.helper.ts
+++ b/src/lib/services/posts.helper.ts
@@ -62,7 +62,7 @@ export function extractBlogPostFromPage(p: PageObjectResponse): BlogPost {
 
   const groupName = getSelectValue(p.properties.group);
   const part = getSelectValue(p.properties.part);
-  const language = getSelectValue(p.properties.language) || 'ko';
+  const language = getSelectValue(p.properties.language) || 'KR';
   const translationId = getRelationId(p.properties.translation);
   const viewCount = getNumberValue(p.properties.view_count);
   const commentCount = getNumberValue(p.properties.comment_count);
diff --git a/src/lib/services/posts.service.ts b/src/lib/services/posts.service.ts
index 6661dbd..573a49b 100644
--- a/src/lib/services/posts.service.ts
+++ b/src/lib/services/posts.service.ts
@@ -20,6 +20,12 @@ const getCachedAllPosts = unstable_cache(async (): Promise<BlogPost[] | null> =>
   try {
     response = await notion.dataSources.query({
       data_source_id: dataSourceId,
+      filter: {
+        property: "published_date",
+        date: {
+          before: new Date().toISOString(),
+        },
+      },
       sorts: [
         {
           timestamp: "created_time",
@@ -37,7 +43,7 @@ const getCachedAllPosts = unstable_cache(async (): Promise<BlogPost[] | null> =>
     .map(extractBlogPostFromPage);
 
   return posts;
-}, ['all-posts-v4'], { revalidate: 3600 });
+}, ['all-posts-v5'], { revalidate: 3600 });
 
 export interface GetPublishedPostsOptions {
   tag?: string;
@@ -75,8 +81,15 @@ export const getPublishedPosts = async (options: GetPublishedPostsOptions = {}):
     // Filter by locale (Language property)
     // Map 'en' locale to 'EN' property value, 'ko' to 'KR' (or whatever is used in Notion)
     // Assuming Notion uses 'KR' and 'EN' as select options
-    const targetLang = locale === 'ko' ? 'KR' : 'EN';
-    if (post.language && post.language !== targetLang) return false;
+    if (post.language) {
+      if (locale === 'ko') {
+        // For Korean locale, accept 'KR', etc.
+        if (post.language !== 'KR') return false;
+      } else {
+        // For English locale, strictly check for 'EN'
+        if (post.language !== 'EN') return false;
+      }
+    }
     
     // Filter by tags (multi-tag AND filtering)
     if (selectedTags.length > 0) {