This is a full-stack microservice-based application built using:
- Frontend: React.js / Next.js(Pending)
- Backend: FastAPI (Ongoing)
- Databases: PostgreSQL and MongoDB
- Containerization: Docker (multi-stage Dockerfiles)
- User Service: Handles authentication, registration, and user management.
- Inventory Service: Manages stock levels, warehouses, and inventory operations.
- Product Service: Maintains product data, categories, and pricing.
- (Upcoming) Payment Service: Will manage transactions, payment gateways, and order settlements.
Each microservice is containerized using a multi-stage Dockerfile for optimized production builds. Each service have it's own docker-compose.yml to run servicess independently for testing/development.
- Authentication and Authorization
- RESTful APIs (FastAPI, Django REST Framework)
- PostgreSQL and MongoDB as backend databases
- Modern frontend with React.js and Next.js
- Dockerized with multi-stage builds
- Scalable and modular microservice architecture
- Docker
- Docker Compose
# Clone the repo
git clone https://github.com/Swapno963/Microservice-with-FastAPI.git
cd Microservice-with-FastAPI
# Build and start all services
docker-compose up --build
A dedicated microservice for managing all user-related functionality. This service handles user authentication, profile management, and account security. postgres is used as database.
This microservice includes the following key functionalities:
- Registration: New user account creation.
- Login: User authentication to grant access.
- Token Management: Ability to get a new access token using a refresh token.
- User Profile: Retrieve and update user profile information.
- Password Management: Securely change user passwords.
- Address Management: Create and manage user addresses.
- Account Verification: Verify if a user account already exists.
A microservice for managing all product-related functionality. This service handles product creation, update. Mongodb is used as database.
This microservice includes the following key functionalities:
- Products: Get all the products
- product: Create Product
- Product: See Detail/Update/Delete product
- Category: Get category list.
This handel inventory-related functionality. This service handles Create Inventory, Check Inventory, Update inventory and keeping inventory history, Reserve inventory quantiry and keeping history of it,Relese inventory quantiry and keeping history of it,Check low stock and send mail. Postgres is used as database.
- Create inventory: Create, update inventory for a product, get inventory items
- reserve: Reserve inventory of a specific product
- release: release inventory of a specific product
- adjust: Add/Remove inventory of a specific product
- low-stockst: Returns all the products whose available_quantity is low compare to reorderd_threshold
- history: Get history of a specific product
A microservice for managing all Order-related functionality. This service handles product order,get all oraders, update order, cancle order. Mongodb is used as database.
This microservice includes the following key functionalities:
- orders: Check inventory availability for all the products. Reserve inventory for all the products. Create the order in the pending status
- orders: Get all orders with optional filtering. This endpoint allows filtering by:
- Order status
- User ID
- Date range
- orders<order_id>: Get a single order by ID.
- /user/{user_id}: Get all orders for a specific user.
- /{order_id}/status: Update the status of an order. This will validate the status transition and update inventory as needed.
- /{order_id}: Cancel an order (if not shipped). This will set the order status to cancelled and release inventory.
This platform evolves from a single-vendor e-commerce system into a multi-vendor SaaS solution, where:
Small business owners (vendors) can register and manage their own stores Customers can browse and purchase from multiple vendors The platform earns revenue via subscription or per-user/per-request pricing
- Core Actors 2.1 Admin (Platform Owner) Manages the entire system Controls vendors, pricing, and policies 2.2 Vendor (Business Owner) Registers to sell products Manages store, inventory, and orders 2.3 Customer Browses products Places orders Interacts with vendors
- SaaS Business Model Pricing Options (Configurable) Subscription-based (monthly/yearly) Per-user pricing (vendor team members) Per-transaction fee Freemium (limited features)
- Feature Breakdown 4.1 Authentication & Authorization Features User registration (Customer / Vendor) Login / Logout Role-based access control (RBAC) Email verification Password reset Advanced (Production-level) OAuth (Google, Facebook) Multi-factor authentication (MFA) 4.2 Vendor Management Features Vendor onboarding Business name Contact details Store metadata Vendor dashboard Vendor approval workflow (manual/auto) Advanced Vendor tier system (Basic / Pro / Enterprise) Store customization (logo, theme) 4.3 Product Management Features Create / Update / Delete products Product categories Product variants (size, color, etc.) Inventory management Pricing and discount setup Advanced Bulk upload (CSV) AI-assisted product description Multi-warehouse inventory 4.4 Marketplace (Customer Side) Features Product browsing Search and filtering Product details page Add to cart Wishlist Advanced Personalized recommendations Recently viewed products Multi-vendor cart handling 4.5 Order Management Features Place order Multi-vendor order splitting Order tracking Order history Vendor Side Accept / Reject orders Update order status Advanced Partial fulfillment Returns and refunds 4.6 Payment System Features Payment gateway integration Order payment processing Advanced Vendor payout system Commission handling Wallet system 4.7 Subscription & Billing (SaaS Core) Features Vendor subscription plans Billing cycle management Usage tracking Advanced Pay-per-request billing Auto invoice generation Payment failure handling 4.8 Reviews & Ratings Features Product reviews Vendor ratings Advanced Review moderation Fraud detection 4.9 Notifications Features Email notifications Order updates Advanced SMS / Push notifications Event-driven notifications 4.10 Admin Panel Features Vendor management Product moderation Order monitoring Revenue tracking Advanced Analytics dashboard Fraud detection tools
- Non-Functional Requirements 5.1 Scalability Support multiple vendors and high traffic Horizontal scaling 5.2 Performance Fast product search Optimized DB queries 5.3 Security Data isolation between vendors (multi-tenancy) Secure payments Rate limiting 5.4 Reliability Fault-tolerant services Backup and recovery
- Architecture Considerations MVP (Junior mindset) Monolith application Shared database Simple role-based filtering Production-grade (Senior mindset)
A senior engineer thinks:
“This is not just e-commerce, this is a multi-tenant SaaS system.”
So they design for:
Tenant isolation (logical or physical) Microservices (optional evolution) Event-driven architecture (orders, payments) Read-heavy optimization (caching, search engine like Elasticsearch) 7. Multi-Tenancy Strategy Option 1: Shared Database (Row-level isolation) vendor_id in every table Option 2: Schema per Vendor Better isolation More complex Option 3: Database per Vendor Maximum isolation High operational cost 8. Future Enhancements AI product recommendation Vendor analytics dashboard Affiliate marketing system Internationalization (multi-language, currency) Mobile app support 9. DevOps & Deployment Considerations Junior View “Deploy app with Docker” Senior View CI/CD pipelines Blue-green deployments Observability (logs, metrics, tracing) Rate limiting & API gateway Database migration strategy 10. Risks & Challenges Multi-vendor cart complexity Payment split & vendor payout Data isolation bugs (critical) Scaling search and filtering Vendor misuse / fraud 11. MVP Scope (Recommended First Release)
To avoid over-engineering:
Vendor registration Product management Basic marketplace Single payment flow Simple subscription plan