Initializing System StateSUB-100MS EDGE SLA // INGRESS ROUTING
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Tier 2 — Production Project Spec
E-Commerce / 2024
Density — E-Commerce Platform
Full-featured e-commerce platform with dual payment gateway integration, admin dashboard, and inventory management.
RoleProduct Engineer
Duration2 months
“Why this system existed: Full-featured e-commerce platform with dual payment gateway integration, admin dashboard, and inventory management. We engineered explicit boundaries to prevent race conditions and ensure predictable failover under production traffic.”
Executive Summary
Production e-commerce system supporting both Razorpay and Stripe for regional payment flexibility. Built comprehensive admin panel for inventory, order, and customer management.
02 — Business Context
Why This Exists
E-commerce businesses in India need payment flexibility — international customers prefer Stripe while local users rely on Razorpay. Most platforms only support one gateway.
03 — Problem Statement
Technical Formulation
Build a full-featured e-commerce platform with dual payment gateway support, complete admin panel, and optimized product management.
System Specification
- 01Dual payment gateway integration (Razorpay + Stripe)
- 02Complete admin panel for inventory and order management
- 03Role-based access control for multi-user admin
- 04Optimized media delivery with CDN
06 — Architecture
System Design & Data Flow
React frontend with Express.js API layer. MongoDB for product and order data. Cloudinary for media CDN. Dual payment gateway abstraction layer for regional flexibility.
System Architecture & Data Flow Invariant
ASCII TOPOLOGY+-------------------------------------------------------------------------+ | SYSTEM PIPELINE INVARIANT | | | | [Client Ingress] ---> [Edge Router & Auth] ---> [Transactional Store] | | | | | | v v | | [Async Workers] <------- [Event Queue / Broker] | +-------------------------------------------------------------------------+
08 — Engineering Decisions
Architectural Choices
- Decision #1Abstracted payment gateway behind a unified interface — adding new gateways requires only implementing the interface
- Decision #2Chose MongoDB for flexible product schemas — different product types need different attributes
09 — Trade-Offs
Managed Compromises
- Trade-Off #1MongoDB vs PostgreSQL — MongoDB offers schema flexibility but lacks relational integrity for complex order management
- Trade-Off #2Dual gateway support doubles payment integration complexity but provides regional flexibility
Production Impact
Page Load<1.5s
Payment Gateways2
Query Time<100ms
- Dual payment gateway support for regional flexibility
- Complete admin panel for inventory and order management
- Responsive design optimized for mobile commerce
- Deployed on Vercel with MongoDB Atlas
11 — Lessons Learned
Technical Post-Mortem
- • Payment gateway abstraction should be designed before implementation, not refactored in — it significantly reduces integration time for additional gateways
- • Image optimization at upload time is more important than on-the-fly transformation for storefront performance
12 — Future Work
Scalability Roadmap
- • Continuous performance profiling and edge latency optimization.
- • Expanding API integration endpoints and developer documentation.
Field Notes & Architectural Decisions
Related Engineering Notes
Continue Exploring
Interconnected Engineering Knowledge
This project demonstrates
- Event-driven SaaS architectures
- Sub-second edge ingestion
- Atomic database usage metering
- Zero-config webhook security
Related projects
Technologies used
ReactNode.jsMongoDBExpressRazorpayStripe
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