Robux Marketplace Website
1+ years | Solo Project | Long-term Project
A full-featured web platform designed for buying, selling, and managing Robux transactions. The system supports multi-language, integrates real-time communication, and provides a secure wallet system with multiple payment methods. It ensures customer protection through automated warranty, refund handling, and detailed transaction tracking.
Contact to build a similar websiteProject Overview
This project demonstrates the ability to design, build, and maintain a complex full-stack web system for online Robux trading. It covers the full development cycle, including authentication, secure transactions, real-time communication, wallet management, and multi-role access control.
Beyond just coding, the project simulates a real-world e-commerce platform with features such as multi-language support, agent management with commission tracking, automated notifications (email & Telegram), and a buyer protection system with automated warranty and refund handling.
What makes this project more valuable is that I not only handled the technical aspects but also interacted directly with users and clients over a long period of time to resolve issues, gather feedback, and continuously improve the product. This experience reflects the real challenges of maintaining a live system, ensuring customer satisfaction, and evolving the platform to meet growing needs.
By working solo on this long-term project, I gained hands-on experience in system architecture design, scalable database management, front-end development, back-end services, and deployment strategies. This showcases not only my technical expertise but also my ability to manage product growth, handle complex challenges, and deliver a professional-grade solution from scratch.
Key Features
- User authentication and authorization
- Quick login with Google
- Multi-language support
- Buy Robux instantly, pre-order, or purchase small amounts
- Personal wallet management with multi-currency support (VND, USD)
- Secure online top-up with bank QR integration
- Order/Transactions tracking, history, and detailed reporting
- Real-time chat between users, agents, and admins
- Agent management with commission-based sales
- Withdrawal system for agents
- Automated warranty and refund handling for failed orders
- Admin tools for order approval, agent review, and fund adjustment
- Automatic notifications via website, email, and Telegram
- User data and profile management
- Scalable performance tested with 1500+ users
- Cloudflare integration for anti-DDoS and enhanced security
- Responsive design across desktop, tablet, and mobile devices
Challenge & Solution
Challenge: Authentication & Authorization
Ensuring account security and clear role-based access for users, agents, and admins.
Solution: Implemented JWT with refresh tokens, role-based access control, and optional 2FA for enhanced security.
Challenge: Multi-language Support
Users from different regions require localized experiences.
Solution: Built an languges system that allows easy addition and management of translations.
Challenge: Flexible Order System (Instant Buy, Pre-order, Small-amount Purchase)
Handling three different purchase flows without transaction conflicts.
Solution: Designed a flexible order system with separate logic branches and queuing to prevent overselling.
Challenge: Preventing Duplicate Orders
When multiple users try to purchase at the same time, there is always a risk of duplicate sales — where two people accidentally buy the same account. This is a common concurrency problem in digital goods marketplaces.
Solution: One-Account-One-Order Design To eliminate this risk, the system was designed so that each order corresponds to exactly one Roblox account. Once an account is purchased, it is instantly locked and marked as “sold,” making it unavailable for other users.
Challenge: Order Tracking & History
Users need real-time visibility into order progress.
Solution: Developed an order tracking system with detailed status updates and searchable transaction history.
Challenge: Personal Wallet with Multi-currency
Supporting multiple currencies (VND, USD) while maintaining accurate balance tracking.
Solution: Created dedicated personal wallets per user, applied standardized exchange rates depend on Admin, and logged every transaction in detail.
Challenge: Wallet Balance Consistency
Handling high-frequency balance updates automatically for multiple users at the same time can cause race conditions or inaccurate balances if not managed properly.
Solution: Implemented an automated transaction system with strict concurrency control to ensure every operation is processed automatically. Each transaction is logged, verified, and synchronized, guaranteeing accurate and consistent wallet balances without manual intervention.
Challenge: Multiple Payment Methods with Security
Payments must be safe and fraud-proof.
Solution: Integrated PayOS QR and The sieu re with encrypted data, checksum/HMAC verification, and fraud detection.
Challenge: Promotions & Discount Codes
Running sales campaigns without conflicts or abuse of discount codes.
Solution: Created a discount engine with rules (usage limit, per-user restriction) to prevent misuse.
Challenge: Agent Management & Commission Tracking
Managing agents, their revenue, and commissions without abuse.
Solution: Built a dedicated agent management system with full transaction logs and automated commission calculation.
Challenge: Agent Withdrawal System
Agents require fast withdrawals while ensuring platform safety.
Solution: Implemented a withdrawal process with admin approval, OTP/email verification (valid agency), and complete audit logs.
Challenge: Real-time Chat & Customer Support
Customers and agents require quick communication to resolve issues.
Solution: Integrated SignalR real-time chat system with notifications, ensuring faster support and higher satisfaction.
Challenge: Notifications & Order Tracking
Users, agents, admin must be notified of order, payment, and system updates instantly.
Solution: Built a multi-channel notification system (in-app, email, Telegram bot) with background queue processing.
Challenge: User & Admin Management
Admins require strong tools to supervise and control the platform.
Solution: Delivered an admin dashboard with user management, wallet editing, transaction monitoring, and activity logs.
Challenge: Scalability & DDoS Protection
The system must remain stable with growing user base and avoid downtime due to attacks.
Direct access to the VPS exposed its real IP address, making it vulnerable to DDoS attacks and other malicious traffic.
The server experienced performance drops during high traffic due to lack of traffic filtering.
Misconfigured Cloudflare rules initially caused false positives, blocking some legitimate users.
Solution: Deployed with Cloudflare DDoS protection and horizontal scalability support for handling high traffic. Enabled Cloudflare’s Full Proxy mode to completely mask the origin server IP. Set up Firewall Rules and Page Rules in Cloudflare to block known bots, limit request rates, and challenge suspicious traffic. Monitored real-time traffic via Cloudflare analytics to fine-tune the protection.
Challenge: Long-term Maintenance & Continuous Updates
The platform evolves with user needs and requires fixes over time.
Solution: Adopted agile iteration with continuous feedback from customers and agents, applying updates and optimizations regularly.
Project Highlights
Delivered stable and accurate order processing: Designed the Robux order system to handle one-by-one transactions with high reliability. Each purchase is executed instantly, ensuring users receive their Robux without delays or errors.
Ensured accurate wallet transactions: Implemented an automated balance system for wallet. Prevented race conditions by isolating transactions per request, ensuring consistent and precise wallet balances for all users.
Scaled to 1500+ users with reliable performance: The system successfully handled over 1500 active users, maintaining stability during peak hours with optimized database queries and efficient transaction logging. Designed to grow smoothly as user demand increases.
Automated warranty & dispute system: Developed an automated warranty system where users can report faulty orders within the warranty period. Agents must resolve the issue, and in case of disputes, admins intervene for final judgment.
High-level security with Cloudflare: Protected the system with Cloudflare to mitigate DDoS attacks, mask server IP, and ensure availability for large-scale usage.
Real-time multi-channel notifications: Implemented automatic notifications across in-app, email, and Telegram bot channels for every critical action — new orders, payment confirmation, reports, dispute updates — keeping users and agents always informed.
Advanced agent management system: Provided agents with tools to sell Robux, manage members, handle reports, and track commissions, ensuring transparency and efficiency.
Seamless multi-currency payment integration: Supported online wallet top-ups with VND & USD via QR PayOS and other gateways, with automated balance updates and detailed transaction history.
Project Info
Category: Web Application
My Role: Full-Stack Developer
Duration: 1+ years (Long-term Project)
Team Size: Solo Project
Technologies: ASP.NET Core Razor Pages, ASP.NET Core API, Entity Framework Core, Html, Css, Js, SignalR, Google OAuth 2.0, JWT, SQL Server, Payos, TheSieuRe, Cloudflare, Telegram API, Email SMTP, IIS
Quick Stats: Long-term project, 1500+ Users, Built By 100% Solo, Security with Cloudflare, JWT Authentication, SSL, Multiple Languages, Responsive, Multiple Payment, Chat Real-time, Automatic Notifications, Personal Wallet, Deployed
