diff --git a/.app.pid b/.app.pid
index e43e440..4c5a421 100644
--- a/.app.pid
+++ b/.app.pid
@@ -1 +1 @@
-96509
+97312
diff --git a/server.ts b/server.ts
index 4814267..3591b2b 100644
--- a/server.ts
+++ b/server.ts
@@ -815,6 +815,42 @@ app.post("/api/jobs/import", (req, res) => {
   }
 });
 
+// API 14: Local Disk Storage Persistence Engine (No Cloud / Firebase Required)
+const DATA_FILE = path.join(process.cwd(), ".data.json");
+import fs from "fs";
+
+app.get("/api/local/data", (req, res) => {
+  try {
+    const key = String(req.query.key || "");
+    if (!fs.existsSync(DATA_FILE)) {
+      return res.json({});
+    }
+    const raw = fs.readFileSync(DATA_FILE, "utf-8");
+    const store = JSON.parse(raw || "{}");
+    res.json(store[key] || {});
+  } catch (e: any) {
+    res.status(500).json({ error: e.message });
+  }
+});
+
+app.post("/api/local/data", (req, res) => {
+  try {
+    const { key, items, profile } = req.body;
+    let store: any = {};
+    if (fs.existsSync(DATA_FILE)) {
+      try { store = JSON.parse(fs.readFileSync(DATA_FILE, "utf-8") || "{}"); } catch (e) {}
+    }
+    if (key) {
+      if (items !== undefined) store[key] = { items };
+      if (profile !== undefined) store[key] = { profile };
+    }
+    fs.writeFileSync(DATA_FILE, JSON.stringify(store, null, 2));
+    res.json({ success: true });
+  } catch (e: any) {
+    res.status(500).json({ error: e.message });
+  }
+});
+
 // API 10: Google Drive - List Job Application Artifacts
 app.get("/api/workspace/drive/files", async (req, res) => {
   try {
diff --git a/src/lib/firebase.ts b/src/lib/firebase.ts
index 849e907..de60785 100644
--- a/src/lib/firebase.ts
+++ b/src/lib/firebase.ts
@@ -1,185 +1,132 @@
-import { initializeApp, getApps, getApp } from 'firebase/app';
-import { 
-  getFirestore, 
-  collection, 
-  doc, 
-  getDocs, 
-  getDoc, 
-  setDoc, 
-  updateDoc, 
-  deleteDoc, 
-  addDoc, 
-  query, 
-  orderBy 
-} from 'firebase/firestore';
-import firebaseConfig from '../../firebase-applet-config.json';
 import { JobApplication, UserProfile, NotificationLog, CalendarInterviewEvent } from '../types';
 
-const app = getApps().length === 0 ? initializeApp(firebaseConfig) : getApp();
-export const db = getFirestore(app);
+export const isFirebaseConfigured = false;
 
-const APPS_COLLECTION = 'applications';
-const PROFILE_DOC = 'user_profile';
-const NOTIFICATIONS_COLLECTION = 'notifications';
-const CALENDAR_COLLECTION = 'calendar_events';
+// 100% Pure Local Disk & LocalStorage Persistence System
 
-export const isFirebaseConfigured = true;
-
-// Firestore Helper Functions with LocalStorage Sync Fallback
+const STORAGE_KEYS = {
+  APPLICATIONS: 'ai_job_portal_applications',
+  USER_PROFILE: 'ai_job_portal_profile',
+  NOTIFICATIONS: 'ai_job_portal_notifications',
+  CALENDAR: 'ai_job_portal_calendar'
+};
 
 export async function fetchApplications(): Promise<JobApplication[]> {
   try {
-    const q = query(collection(db, APPS_COLLECTION));
-    const snapshot = await getDocs(q);
-    if (snapshot.empty) return [];
-    return snapshot.docs.map(docSnap => ({ id: docSnap.id, ...docSnap.data() } as JobApplication));
-  } catch (err) {
-    console.warn('Firestore fetch failed, using local storage cache:', err);
-    const local = localStorage.getItem('ai_job_portal_applications');
-    return local ? JSON.parse(local) : [];
+    const res = await fetch('/api/local/data?key=' + STORAGE_KEYS.APPLICATIONS);
+    if (res.ok) {
+      const data = await res.json();
+      if (Array.isArray(data.items)) return data.items;
+    }
+  } catch (e) {
+    console.warn('Local API read failed, reading from browser localStorage');
   }
+  const local = localStorage.getItem(STORAGE_KEYS.APPLICATIONS);
+  return local ? JSON.parse(local) : [];
 }
 
 export async function saveApplication(appData: Omit<JobApplication, 'id'> & { id?: string }): Promise<JobApplication> {
   const id = appData.id || `app_${Date.now()}_${Math.random().toString(36).substring(2, 7)}`;
   const record: JobApplication = { ...appData, id };
 
-  try {
-    await setDoc(doc(db, APPS_COLLECTION, id), record, { merge: true });
-  } catch (err) {
-    console.warn('Firestore save failed, caching locally:', err);
-  }
-
-  // Update local storage backup
-  const localApps = localStorage.getItem('ai_job_portal_applications');
-  const list: JobApplication[] = localApps ? JSON.parse(localApps) : [];
+  const list = await fetchApplications();
   const idx = list.findIndex(a => a.id === id);
   if (idx >= 0) list[idx] = record;
   else list.unshift(record);
-  localStorage.setItem('ai_job_portal_applications', JSON.stringify(list));
+
+  localStorage.setItem(STORAGE_KEYS.APPLICATIONS, JSON.stringify(list));
+
+  try {
+    await fetch('/api/local/data', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ key: STORAGE_KEYS.APPLICATIONS, items: list })
+    });
+  } catch (e) {
+    console.warn('Failed to sync to local disk file');
+  }
 
   return record;
 }
 
-export async function updateApplicationStatus(id: string, newStatus: JobApplication['status'], note?: string): Promise<void> {
-  const timestamp = new Date().toLocaleDateString('en-US', { month: 'short', day: 'numeric', hour: '2-digit', minute: '2-digit' });
-  const timelineItem = { date: timestamp, action: `Status changed to ${newStatus}`, details: note };
-
-  try {
-    const docRef = doc(db, APPS_COLLECTION, id);
-    const snap = await getDoc(docRef);
-    if (snap.exists()) {
-      const existing = snap.data() as JobApplication;
-      const timeline = existing.timeline || [];
-      timeline.unshift(timelineItem);
-      await updateDoc(docRef, { status: newStatus, timeline });
-    }
-  } catch (err) {
-    console.warn('Firestore update failed:', err);
-  }
-
-  // Local storage update
-  const localApps = localStorage.getItem('ai_job_portal_applications');
-  if (localApps) {
-    const list: JobApplication[] = JSON.parse(localApps);
-    const idx = list.findIndex(a => a.id === id);
-    if (idx >= 0) {
-      list[idx].status = newStatus;
-      if (!list[idx].timeline) list[idx].timeline = [];
-      list[idx].timeline!.unshift(timelineItem);
-      localStorage.setItem('ai_job_portal_applications', JSON.stringify(list));
-    }
+export async function updateApplicationStatus(id: string, status: JobApplication['status'], note?: string): Promise<void> {
+  const list = await fetchApplications();
+  const target = list.find(a => a.id === id);
+  if (target) {
+    target.status = status;
+    if (note) target.notes = note;
+    if (!target.timeline) target.timeline = [];
+    target.timeline.unshift({
+      date: new Date().toLocaleDateString() + ' ' + new Date().toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' }),
+      action: `Status updated to ${status}`
+    });
+    await saveApplication(target);
   }
 }
 
 export async function deleteApplicationRecord(id: string): Promise<void> {
-  try {
-    await deleteDoc(doc(db, APPS_COLLECTION, id));
-  } catch (err) {
-    console.warn('Firestore delete failed:', err);
-  }
+  const list = await fetchApplications();
+  const updated = list.filter(a => a.id !== id);
+  localStorage.setItem(STORAGE_KEYS.APPLICATIONS, JSON.stringify(updated));
 
-  const localApps = localStorage.getItem('ai_job_portal_applications');
-  if (localApps) {
-    const list: JobApplication[] = JSON.parse(localApps);
-    const filtered = list.filter(a => a.id !== id);
-    localStorage.setItem('ai_job_portal_applications', JSON.stringify(filtered));
-  }
+  try {
+    await fetch('/api/local/data', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ key: STORAGE_KEYS.APPLICATIONS, items: updated })
+    });
+  } catch (e) {}
 }
 
 export async function fetchUserProfile(): Promise<UserProfile | null> {
   try {
-    const snap = await getDoc(doc(db, 'profiles', PROFILE_DOC));
-    if (snap.exists()) return snap.data() as UserProfile;
-  } catch (err) {
-    console.warn('Firestore fetch profile failed:', err);
-  }
-  const local = localStorage.getItem('ai_job_portal_user_profile');
+    const res = await fetch('/api/local/data?key=' + STORAGE_KEYS.USER_PROFILE);
+    if (res.ok) {
+      const data = await res.json();
+      if (data.profile) return data.profile;
+    }
+  } catch (e) {}
+
+  const local = localStorage.getItem(STORAGE_KEYS.USER_PROFILE);
   return local ? JSON.parse(local) : null;
 }
 
 export async function saveUserProfile(profile: UserProfile): Promise<void> {
+  localStorage.setItem(STORAGE_KEYS.USER_PROFILE, JSON.stringify(profile));
+
   try {
-    await setDoc(doc(db, 'profiles', PROFILE_DOC), profile, { merge: true });
-  } catch (err) {
-    console.warn('Firestore save profile failed:', err);
-  }
-  localStorage.setItem('ai_job_portal_user_profile', JSON.stringify(profile));
+    await fetch('/api/local/data', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ key: STORAGE_KEYS.USER_PROFILE, profile })
+    });
+  } catch (e) {}
 }
 
 export async function fetchNotifications(): Promise<NotificationLog[]> {
-  try {
-    const q = query(collection(db, NOTIFICATIONS_COLLECTION));
-    const snap = await getDocs(q);
-    return snap.docs.map(d => ({ id: d.id, ...d.data() } as NotificationLog));
-  } catch (err) {
-    const local = localStorage.getItem('ai_job_portal_notifications');
-    return local ? JSON.parse(local) : [];
-  }
+  const local = localStorage.getItem(STORAGE_KEYS.NOTIFICATIONS);
+  return local ? JSON.parse(local) : [];
 }
 
-export async function saveNotificationLog(notif: Omit<NotificationLog, 'id'>): Promise<NotificationLog> {
+export async function saveNotificationLog(notifData: Omit<NotificationLog, 'id'>): Promise<NotificationLog> {
   const id = `notif_${Date.now()}_${Math.random().toString(36).substring(2, 6)}`;
-  const record: NotificationLog = { ...notif, id };
-  try {
-    await setDoc(doc(db, NOTIFICATIONS_COLLECTION, id), record);
-  } catch (err) {
-    console.warn('Firestore save notification failed:', err);
-  }
-
-  const local = localStorage.getItem('ai_job_portal_notifications');
-  const list: NotificationLog[] = local ? JSON.parse(local) : [];
+  const record: NotificationLog = { ...notifData, id };
+  const list = await fetchNotifications();
   list.unshift(record);
-  localStorage.setItem('ai_job_portal_notifications', JSON.stringify(list));
-
+  localStorage.setItem(STORAGE_KEYS.NOTIFICATIONS, JSON.stringify(list));
   return record;
 }
 
 export async function fetchCalendarEvents(): Promise<CalendarInterviewEvent[]> {
-  try {
-    const snap = await getDocs(collection(db, CALENDAR_COLLECTION));
-    return snap.docs.map(d => ({ id: d.id, ...d.data() } as CalendarInterviewEvent));
-  } catch (err) {
-    const local = localStorage.getItem('ai_job_portal_calendar');
-    return local ? JSON.parse(local) : [];
-  }
+  const local = localStorage.getItem(STORAGE_KEYS.CALENDAR);
+  return local ? JSON.parse(local) : [];
 }
 
-export async function saveCalendarEvent(event: Omit<CalendarInterviewEvent, 'id'> & { id?: string }): Promise<CalendarInterviewEvent> {
-  const id = event.id || `evt_${Date.now()}_${Math.random().toString(36).substring(2, 6)}`;
-  const record: CalendarInterviewEvent = { ...event, id };
-  try {
-    await setDoc(doc(db, CALENDAR_COLLECTION, id), record, { merge: true });
-  } catch (err) {
-    console.warn('Firestore save calendar event failed:', err);
-  }
-
-  const local = localStorage.getItem('ai_job_portal_calendar');
-  const list: CalendarInterviewEvent[] = local ? JSON.parse(local) : [];
-  const idx = list.findIndex(e => e.id === id);
-  if (idx >= 0) list[idx] = record;
-  else list.push(record);
-  localStorage.setItem('ai_job_portal_calendar', JSON.stringify(list));
-
+export async function saveCalendarEvent(eventData: Omit<CalendarInterviewEvent, 'id'> & { id?: string }): Promise<CalendarInterviewEvent> {
+  const id = eventData.id || `evt_${Date.now()}_${Math.random().toString(36).substring(2, 6)}`;
+  const record: CalendarInterviewEvent = { ...eventData, id };
+  const list = await fetchCalendarEvents();
+  list.push(record);
+  localStorage.setItem(STORAGE_KEYS.CALENDAR, JSON.stringify(list));
   return record;
 }