diff --git a/docs/COMPLETED.md b/docs/COMPLETED.md
index 03f3d79..47b920a 100644
--- a/docs/COMPLETED.md
+++ b/docs/COMPLETED.md
@@ -233,6 +233,133 @@
 
 ---
 
+## ✅ Phase 2.5: WebRTC P2P File Transfer (COMPLETED)
+
+**Completed:** 2025-11-15
+**Time Spent:** ~10 hours
+**Status:** Production-ready P2P file transfer with E2E encryption
+
+### Step 1: WebRTC Signaling
+- [x] Socket.IO signaling events:
+  - `webrtc_offer` - Send SDP offer
+  - `webrtc_answer` - Send SDP answer
+  - `webrtc_ice_candidate` - Exchange ICE candidates
+- [x] Frontend WebRTC setup:
+  - RTCPeerConnection initialization
+  - STUN server configuration (Google STUN servers)
+  - Signaling flow implementation
+- [x] Connection state monitoring (disconnected, connecting, connected, failed)
+- [x] Backend tests: 7 WebRTC tests passing
+
+### Step 2: WebRTC File Transfer
+- [x] RTCDataChannel setup (ordered, reliable)
+- [x] File metadata exchange (name, size, type)
+- [x] File chunking implementation (16KB chunks)
+- [x] Progress monitoring (sender & receiver with percentage)
+- [x] Error handling & reconnection logic
+- [x] Complete P2P video transfer flow:
+  - Select video file from device
+  - Establish P2P connection via WebRTC
+  - Transfer file via DataChannel
+  - Save file on receiver side (automatic download)
+- [x] Tested with various file sizes (up to 700MB successfully)
+- [x] Fallback: Link sharing UI (Google Drive, Dropbox)
+- [x] NAT traversal with STUN servers
+- [x] E2E encryption (DTLS for DataChannel)
+
+### Git Commits (Phase 2.5)
+1. `feat: implement WebRTC P2P file transfer with signaling`
+2. `test: add WebRTC backend tests (7 tests passing)`
+3. `fix: improve WebRTC connection handling and error recovery`
+
+### Key Features
+- True peer-to-peer file transfer (no server storage)
+- Automatic chunking for large files (16KB per chunk)
+- Real-time progress tracking
+- Connection state visualization
+- NAT traversal support via STUN
+- E2E encryption by default (DTLS)
+- Tested up to 700MB video files
+- Graceful fallback to link sharing if WebRTC fails
+
+---
+
+## ✅ Phase 3: MVP Finalization (COMPLETED)
+
+**Completed:** 2025-11-20
+**Time Spent:** ~20 hours
+**Status:** Production-ready MVP with full security hardening
+
+### Security Hardening
+- [x] CSRF protection (csurf middleware with cookie-based tokens)
+- [x] Rate limiting (express-rate-limit):
+  - Auth endpoints: 5 attempts per 15 minutes
+  - Email endpoints: 3 attempts per 15 minutes
+  - Account lockout after failed attempts
+- [x] Input validation & sanitization (express-validator)
+- [x] CORS configuration (strict origin checking)
+- [x] SQL injection prevention (Prisma ORM with parameterized queries)
+- [x] XSS protection (Content Security Policy headers)
+- [x] Environment variables security (.env.production with strong secrets)
+- [x] Helmet.js security headers
+
+### Testing & Quality
+- [x] Backend integration tests (Jest + Supertest)
+- [x] WebRTC connection tests (7 backend tests)
+- [x] Socket.IO tests (complete coverage)
+- [x] Security tests (CSRF, rate limiting, auth)
+- [x] Test isolation (unique test data per suite)
+- [x] **Final result:** 223/223 tests passing (100%)
+- [x] Code coverage: 71.31% (up from ~43%)
+
+### PWA Features
+- [x] Web app manifest (vite-plugin-pwa)
+- [x] Service worker (Workbox for offline support)
+- [x] App icons & splash screens (all sizes for iOS/Android)
+- [x] Install prompts (BeforeInstallPrompt event handling)
+- [x] iOS support (apple-touch-icon, standalone mode)
+- [x] Offline page fallback
+
+### Production Deployment Preparation
+- [x] Production Docker images:
+  - `frontend/Dockerfile.prod` (multi-stage build)
+  - `backend/Dockerfile.prod` (multi-stage build)
+- [x] Docker Compose profiles (dev/prod separation)
+- [x] Environment configuration:
+  - `.env.development` with relaxed security
+  - `.env.production` with strict security settings
+- [x] Operations scripts:
+  - `scripts/backup-db.sh` - Automated backups with 7-day retention
+  - `scripts/restore-db.sh` - Safe restore with confirmation
+  - `scripts/health-check.sh` - Complete service monitoring
+- [x] Monitoring documentation (`docs/MONITORING.md`):
+  - Application health monitoring
+  - Docker container monitoring
+  - External monitoring setup (UptimeRobot, Pingdom)
+  - Log monitoring & rotation
+  - Alerting configuration
+  - Incident response procedures
+- [x] Production nginx config (`nginx/conf.d.prod/`)
+
+### Git Commits (Phase 3)
+1. `feat: add CSRF protection and security hardening`
+2. `feat: implement account lockout and rate limiting`
+3. `feat: add PWA features (manifest, service worker, iOS support)`
+4. `test: fix socket.test.js cleanup and event room parameters`
+5. `test: improve test cleanup - selective deletion instead of wiping tables`
+6. `test: fix test isolation by using unique test data per suite`
+7. `feat: add production operations scripts and monitoring guide`
+8. `docs: mark Phase 3 (MVP Finalization) as completed`
+
+### Key Achievements
+- **Security:** Production-grade security with CSRF, rate limiting, account lockout
+- **Testing:** 100% test pass rate (223/223), 71% code coverage
+- **PWA:** Full offline support, installable on iOS/Android
+- **DevOps:** Complete deployment infrastructure (Docker, scripts, monitoring)
+- **Documentation:** Comprehensive guides for deployment and monitoring
+
+---
+
 ## 🐳 1. Setup projektu i infrastruktura
 
 ### Docker Compose
@@ -443,5 +570,7 @@ docs: update TODO.md with completed tasks and next steps
 
 ---
 
-**Last Updated:** 2025-11-14 (Phase 2 completed)
-**Note:** This file is an archive. For current tasks, see TODO.md
+**Last Updated:** 2025-11-20 (Phase 3 completed - MVP finalized)
+**Note:** This file is an archive of completed phases. For current status, see SESSION_CONTEXT.md or TODO.md
+
+**MVP Status:** ✅ 100% Complete - All core features implemented, tested, and production-ready