MONTRA Lifts

A production-grade, multi-vendor B2B e-commerce platform for the elevator spare parts and lift-systems industry. Connects installers, customers, traders/suppliers, and platform admins through a sophisticated marketplace with smart order routing, project (RFQ) workflows, tamper-proof financial ledgers, and a built-in CMS.

Live: montralifts.com · API: api.montralifts.com · Admin: admin.montralifts.com · Trader: trader.montralifts.com

1. Project at a Glance

Item	Detail
Domain	B2B Marketplace — Elevator Spare Parts & Lift Systems
Market	Egypt (EGP, Arabic + English, RTL/LTR)
Architecture	Monorepo: 1 backend API + 4 independent Next.js apps + MySQL
Backend	NestJS 10, Prisma 5, MySQL 8, JWT, Swagger
Frontend	Next.js 16 (App Router), React 19, TypeScript, TailwindCSS 4, Zustand, React Hook Form + Zod, shadcn/ui, Framer Motion, Recharts
Infra	Docker Compose, Nginx reverse proxy, Let's Encrypt SSL, GitHub Actions CI/CD, VPS
3rd-Party	Paymob (payments, HMAC-validated webhooks), Cloudinary (media), WhatsApp deep-links
Scale	50 Prisma models · 30+ backend modules · 100+ REST endpoints · 4 separate frontends
Status	Production, ~98% complete, actively maintained

2. System Architecture

┌─────────────────────────────────────────────────────────────────┐
│                      FRONTEND APPLICATIONS                       │
├──────────────┬───────────────┬────────────────┬─────────────────┤
│   Landing    │    Client     │     Trader     │      Admin       │
│   :3000      │    :3001      │     :3002      │      :3003       │
│ Public site, │ Marketplace,  │  Supplier      │  Operations,     │
│ CMS-driven   │ projects/RFQ, │  dashboard,    │  CMS, finance,   │
│ blog/SEO     │ cart, returns │  fulfillment   │  trader payouts  │
└──────┬───────┴───────┬───────┴────────┬───────┴─────────┬───────┘
       │               │                │                 │
       └───────────────┴────────┬───────┴─────────────────┘
                                │  HTTPS / REST + JWT
                                ▼
┌─────────────────────────────────────────────────────────────────┐
│                     BACKEND API (NestJS)  :4422                  │
│  Auth · Items · SupplierListings · Orders · SubOrders ·          │
│  Projects/RFQ · Pricing Engine · Commissions · Returns ·         │
│  Payments (Paymob) · DeliveryNotes · CMS · Stock · Excel ·       │
│  Notifications · Activity Logs · Support · Sections (shipping)   │
└────────────────────────────────┬────────────────────────────────┘
                                 │  Prisma ORM
                                 ▼
┌─────────────────────────────────────────────────────────────────┐
│                        MySQL 8.0 — 50 Models                     │
└─────────────────────────────────────────────────────────────────┘

3. The Four Frontends

3.1 Landing Site (`frontend-landing`, port 3000)

Marketing & SEO surface for the brand.

Bilingual (AR/EN) with full RTL/LTR support
CMS-driven content: services, lift types, portfolio, blog, clients, hero
Animated hero & sections (Framer Motion)
Blog with dynamic [slug] routes
Conversion CTAs to the marketplace and trader signup

Routes: /, /landing, /blog, /blog/[slug]

3.2 Client Marketplace (`frontend-client`, port 3001)

Where customers and installers shop and run projects.

Catalog browsing with categories, search, filters, sliders (price/brand)
Item detail pages with multi-supplier pricing, specs, gallery
Wishlist / favorites
Cart + checkout with shipping address management
Paymob payment flow (card/wallet) and cash-on-delivery
Deposit logic for large orders (15–20% gating)
Order tracking, sub-order timeline, invoices
Returns & exchanges workflow (request, track, history)
Projects (RFQ) module: create installation projects, configure BOM, receive supplier offers, accept/reject, convert to a project-order
User profile, addresses, order history
Support / ticketing
Bilingual UI with language switcher

Routes: /, /categories, /items/[id], /cart, /checkout, /favorites, /orders/[id], /projects, /projects/new, /projects/[id], /project-orders/[id], /returns, /returns/new, /returns/[id], /profile, /payment, /invoice, /support, /login, /register

3.3 Trader Dashboard (`frontend-trader`, port 3002)

Where suppliers run their business on the platform.

KPI dashboard (earnings, orders, stock alerts, ratings)
Listings management: create/edit per-item listings with min/max price, stock, reserved stock, lead time, reliability score
Excel import/export of listings (bulk operations)
Pending assignments queue (accept / reject sub-orders)
Sub-order fulfillment: accept → ship → deliver → confirm cash
Supplier orders views: accepted / history
Project orders flow for RFQ-won projects
Returns review & approval
Balance & commission ledger view
Analytics (per-trader): revenue, conversion, top items, trends
Trader settings, service sections (shipping zones), profile, verification
Bilingual UI (AR/EN)

Routes: /dashboard, /dashboard/listings, /dashboard/pending-assignments, /dashboard/sub-orders/[id], /dashboard/supplier-orders/{accepted,history}, /dashboard/projects, /dashboard/project-orders/[id], /dashboard/returns, /dashboard/balance, /dashboard/analytics, /dashboard/settings, /dashboard/support

3.4 Admin Panel (`frontend-admin`, port 3003)

Operational backbone of the platform.

Items catalog (master items used by all suppliers)
Categories (hierarchical)
Traders management & verification
Users management (customers + traders)
Orders (all orders + manual overrides)
Projects & BOM Patterns (reusable bills-of-materials)
Returns management + returns analytics
Stock overview across all suppliers
Sections (geographic shipping zones + distance matrix)
Commissions & commission ledger
Financial / traders (payouts, balances)
Invoices
Analytics (platform-wide, revenue tracking)
Banners (marketplace hero/promo banners)
CMS for the landing site:
- Services
- Lift Types
- Portfolio Projects
- Blog
- Clients (logos / testimonials)
- Hero section
- Marketplace settings
System settings, activity logs, notifications, support tickets

Routes: /dashboard/{items, categories, traders, users, orders, projects, bom-patterns, returns, stock, sections, commissions, financial, invoices, analytics, banners, settings, activity, notifications, support} plus /cms/{services, lift-types, portfolio, blog, clients, hero, settings}

4. Backend (NestJS)

30+ feature modules, organized by domain:

Module	Responsibility
`auth`	JWT + Passport login, customer/trader registration, role guards
`users`	User CRUD, profile, address book
`traders`	Trader profile, verification, sections (shipping zones)
`items`	Admin-owned master catalog (specs, images, category, brand)
`categories`	Hierarchical category tree (parent/children)
`client-items`	Public read API exposing items + cheapest supplier price
`supplier-listings`	Trader listings (price ranges, stock, lead time, reliability)
`orders`	Customer orders, order items, totals, deposit logic
`sub-orders`	Per-trader splits of a master order, with full lifecycle
`projects`	RFQ projects, BOM patterns, supplier offers, project orders
`pricing-engine`	Supplier scoring & multi-strategy assignment algorithm
`commissions`	Platform fee accrual, invoicing, trader ledger, cron jobs
`payments`	Paymob iframe creation + HMAC-validated webhook + COD
`delivery-notes`	Vendor delivery confirmation that triggers commission
`returns`	Customer returns/exchanges, trader review, refund flow
`cms`	Services / lift-types / portfolio / blog / clients / hero / settings
`banners`	Marketplace promotional banners
`sections`	Geographic sections + distance matrix for shipping calc
`shipping`	Shipping cost calculation per section/trader
`stock`	Stock + reservation tracking, low-stock alerts
`excel`	Generic Excel import/export utilities
`upload`	Cloudinary integration for media
`favorites`	Wishlist
`reviews`	Product & trader ratings
`notifications`	In-app notifications
`activity-logs`	Audit trail of important user actions
`support`	Support tickets
`admin`	Platform-wide stats & admin overrides
`internal`	Margin analytics & supplier-selection introspection
`health`	`/health` checks for Docker/Nginx probes
`services`	Domain service utilities shared across modules

Cross-cutting: Swagger/OpenAPI docs, class-validator DTOs, throttling (@nestjs/throttler), scheduled jobs (@nestjs/schedule), Helmet, compression, CORS, centralized error handling.

5. Database (Prisma · MySQL)

50 models across these domains:

Identity: User, TraderProfile, Address
Catalog: Category, Item, SupplierListing, PricingRule, Banner
Orders: Order, OrderItem, SubOrder, SubOrderItem, OrderAssignment, SubOrderAssignment, DeliveryNote
Projects / RFQ: Project, BomPattern, BomPatternItem, ProjectSpecification, BillOfMaterialItem, SupplierOffer, SupplierOfferItem, ProjectOrder, ProjectOrderItem
Money: Invoice, CommissionRecord, CommissionInvoice, TraderLedger, CommissionLedgerEntry
Customer Experience: Review, Favorite, ReturnRequest, ReturnRequestItem, SupportTicket, Notification, ActivityLog
Geo / Shipping: Country, Section, TraderSection, SectionDistance
CMS: Service, LiftType, PortfolioProject, BlogPost, Client, CompanySetting, HeroSection, MarketplaceSetting, FAQ
Config: SystemSetting

All money flows are checksummed (SHA-256) and append-only.

6. Signature Features (the "wow" of the project)

6.1 Smart Multi-Strategy Order Assignment

When a customer order has N items, the platform splits it into SubOrders per trader using one of three strategies:

Strategy	How it picks	Result	Best for
Best Per Item	Highest `supplierScore` per item	Many SubOrders, best quality/price	Premium orders
Most Availability	Trader covering most items, weighted `60% items + 40% quality`	Fewer SubOrders, faster	Speed-critical
Hybrid (default)	1st SubOrder = Most Availability, rest = Best Per Item	3–4 SubOrders, balanced	Most orders

Rejection handling is recursive: when a trader rejects, the system re-runs assignment on the remaining unassigned items while excluding the rejecting trader.

6.2 Projects / RFQ Workflow (Installer-Grade)

Installers configure full elevator projects (buildings × floors × elevators, door type, machine type, control type, cabin, origin preference) — either from scratch or from a saved BOM Pattern. The BOM is broken into categorized items (DOOR / MACHINE / CONTROLLER / RAIL / CABLE / ACCESSORY), suppliers submit multi-item offers with full pricing, and the installer accepts one offer that becomes a ProjectOrder assigned to the winning trader.

6.3 Tamper-Proof Financial Ledger

Every money event is a ledger entry with:

balanceBefore / balanceAfter
SHA-256 checksum linking entry → previous entry
transactionRef for forensics
Append-only — integrity verifiable end-to-end

Entry types: PAYMENT_RECEIVED, DEPOSIT_PAID, COMMISSION_DEDUCTED, TRADER_PAYOUT, REFUND.

6.4 Deposit Engine for Large Orders

Risk-based deposit gating before fulfillment:

Order value	New user	Trusted user (>6 mo)
< 20k EGP	None	None
20k – 100k	15%	None
> 100k	20%	20%

6.5 Commission System

Configurable per-trader rates (default 2.5%, custom override for VIPs)
Platform fee = min(subtotal × 3%, 1000 EGP) capped per order
Commission is accrued on delivery confirmation, invoiced on a schedule (cron), and reconciled via the trader ledger
Statuses: ACCRUED → INVOICED → PAID (plus WAIVED and invoice DRAFT/ISSUED/PAID/OVERDUE/CANCELLED)

6.6 Delivery Notes

Formal delivery confirmation is its own document — AUTO, VENDOR_CLICK, CLIENT_ACK, or ADMIN_OVERRIDE. Only a confirmed delivery note triggers commission accrual, keeping money flows aligned with physical fulfillment.

6.7 Returns & Exchanges

First-class workflow with two types:

EXCHANGE (default — defective item replaced; a new exchange order is created)
REFUND_ONLY (for shipping errors)

Status machine: REQUESTED → UNDER_REVIEW → APPROVED/REJECTED → PROCESSING → COMPLETED/CANCELLED.

6.8 Section-Based Shipping

Geographic Sections with a distance matrix between them; each trader declares which sections they serve and their primary pickup section, allowing realistic shipping cost calculation per sub-order.

6.9 Full Bilingual / RTL System

Every customer-facing surface (landing, client, trader) and the catalog itself (item names, descriptions, CMS content) is bilingual Arabic + English with proper RTL and a language switcher.

6.10 CMS for the Marketing Site

The landing page is fully editable by admins — services, lift types, portfolio projects, blog posts, client logos, hero, FAQs, marketplace settings — all with SEO fields, ordering, slugs, image management, and publish toggles.

6.11 Excel Import / Export

Traders can bulk-manage their listings via Excel round-trip; admins can export reports.

6.12 Paymob Integration

Card + wallet payments with iframe redirect, HMAC SHA-512 signature validation on webhooks, idempotency keys to prevent double-charge, transaction-wrapped DB updates.

7. Security

JWT (Bearer) with role guards: ADMIN | TRADER | CUSTOMER
bcrypt password hashing
Prisma parameterized queries (no SQL injection surface)
Helmet security headers, CORS allowlist, throttling
class-validator DTOs at every controller
Paymob HMAC validation + idempotency
SHA-256 ledger checksums for financial integrity
HTTPS everywhere (Let's Encrypt, auto-renewing)

8. DevOps & Tooling

Local dev: docker-compose.dev.yml with hot-reload across all 5 services; one-shot ./start-dev-env.sh
Production: docker-compose.yml on a VPS, Nginx reverse-proxy in front, four sub-domains (montralifts.com, api., admin., trader.)
CI/CD: GitHub Actions auto-deploys on push to master
Health checks: /api/v1/health (backend) + /_healthz (Next.js apps)
DB tooling: Prisma migrations, seed scripts (prisma:seed, prisma:seed:clean), Prisma Studio
Testing: Jest unit + e2e on backend, fast-check property-based tests for critical algorithms (assignment / pricing)

9. Tech Stack Summary

Backend: NestJS 10 · TypeScript · Prisma 5 · MySQL 8 · JWT + Passport · class-validator · Swagger · Helmet · Throttler · @nestjs/schedule · Multer · Cloudinary · Paymob · xlsx · Axios

Frontend (all 4 apps): Next.js 16 (App Router) · React 19 · TypeScript · TailwindCSS 4 · shadcn/ui · Radix primitives · Zustand · React Hook Form + Zod · SWR / Axios · Framer Motion · Recharts · Lucide · sonner / react-hot-toast

Infra: Docker · Docker Compose · Nginx · Let's Encrypt · GitHub Actions · VPS

10. Numbers

Metric	Count
Frontend applications	4
Backend feature modules	30+
REST endpoints	100+
Prisma models	50
User roles	3 (Customer, Trader, Admin)
Order-assignment strategies	3
Languages supported	2 (AR + EN, RTL/LTR)
Payment methods	Card, Mobile Wallet, Bank Transfer, COD
Production sub-domains	4

11. My Role / What I Built

End-to-end ownership: product architecture, database design, backend (NestJS, Prisma, Paymob integration, smart assignment engine, commission & ledger system, RFQ workflow, returns), all four Next.js frontends (marketplace UX, trader operations, admin tooling, marketing site CMS), i18n (AR/EN + RTL), Docker/Nginx deployment, and CI/CD.

Built for the Egyptian elevator industry · Production-ready · 2026

1. Project at a Glance

2. System Architecture

3. The Four Frontends

3.1 Landing Site (`frontend-landing`, port 3000)

3.2 Client Marketplace (`frontend-client`, port 3001)

3.3 Trader Dashboard (`frontend-trader`, port 3002)

3.4 Admin Panel (`frontend-admin`, port 3003)

4. Backend (NestJS)

5. Database (Prisma · MySQL)

6. Signature Features (the "wow" of the project)

6.1 Smart Multi-Strategy Order Assignment

6.2 Projects / RFQ Workflow (Installer-Grade)

6.3 Tamper-Proof Financial Ledger

6.4 Deposit Engine for Large Orders

6.5 Commission System

6.6 Delivery Notes

6.7 Returns & Exchanges

6.8 Section-Based Shipping

6.9 Full Bilingual / RTL System

6.10 CMS for the Marketing Site

6.11 Excel Import / Export

6.12 Paymob Integration

7. Security

8. DevOps & Tooling

9. Tech Stack Summary

10. Numbers

11. My Role / What I Built

Ajza

Qooty

Mudarris

MONTRA Lifts

1. Project at a Glance

2. System Architecture

3. The Four Frontends

3.1 Landing Site (frontend-landing, port 3000)

3.2 Client Marketplace (frontend-client, port 3001)

3.3 Trader Dashboard (frontend-trader, port 3002)

3.4 Admin Panel (frontend-admin, port 3003)

4. Backend (NestJS)

5. Database (Prisma · MySQL)

6. Signature Features (the "wow" of the project)

6.1 Smart Multi-Strategy Order Assignment

6.2 Projects / RFQ Workflow (Installer-Grade)

6.3 Tamper-Proof Financial Ledger

6.4 Deposit Engine for Large Orders

6.5 Commission System

6.6 Delivery Notes

6.7 Returns & Exchanges

6.8 Section-Based Shipping

6.9 Full Bilingual / RTL System

6.10 CMS for the Marketing Site

6.11 Excel Import / Export

6.12 Paymob Integration

7. Security

8. DevOps & Tooling

9. Tech Stack Summary

10. Numbers

11. My Role / What I Built

Ajza

Qooty

Mudarris

3.1 Landing Site (`frontend-landing`, port 3000)

3.2 Client Marketplace (`frontend-client`, port 3001)

3.3 Trader Dashboard (`frontend-trader`, port 3002)

3.4 Admin Panel (`frontend-admin`, port 3003)