System Design

Overview

RendBit is built around a hybrid architecture that combines custodial wallet simplicity with blockchain-powered settlement. The system ensures that end-users experience a smooth, fintech-like interface while transactions are securely processed on the Stellar network in the background. This hybrid approach balances speed, security, and usability for both individuals and businesses.

The platform’s key actors include wallet users, administrators, and third-party service providers. Users interact with the wallet to deposit, transfer, swap currencies, and access reporting. Administrators handle compliance, monitor activity, and maintain system integrity, while service providers such as banks, payment gateways, and blockchain partners support smooth on-ramps, off-ramps, and interoperability.

RendBit also considers other stakeholders like regulators, auditors, and partner institutions. These stakeholders rely on the platform’s transparent, auditable transactions, real-time reporting, and robust compliance infrastructure. By ensuring trust and accountability at every layer, RendBit strengthens adoption across the African cross-border payments ecosystem.

Network Layer

The network layer of RendBit is designed to support high availability and real-time transaction processing. It combines Stellar’s blockchain for settlement with API-driven services for user interactions, ensuring transactions are both secure and fast. Redundant nodes and caching mechanisms guarantee smooth performance even during high transaction volumes.

Offline support is integrated at the network layer. Users can initiate transactions or deposits while offline, and the system automatically synchronizes them once connectivity is restored. This ensures continuous data availability and reliability in regions with intermittent internet access.

Additionally, RendBit’s network layer handles revoking access and time-locked permissions. Users can control wallet permissions, schedule transfers, and enforce temporary or conditional access for added security. These mechanisms maintain flexibility and trust across all parties interacting with the system.

Fundamental Data Structures

RendBit organizes transactions, wallet accounts, and user data using efficient, query-optimized structures. This supports real-time analytics, reporting, and reconciliation without compromising security or scalability. Sensitive data is encrypted at rest and in transit to prevent unauthorized access.

Key features include optional blockchain address visibility for advanced users. While most users experience a simplified interface, power users can monitor on-chain activity or export addresses for integration with external tools, providing transparency without complexity.

The system also maintains storage and consensus using MongoDB for persistent data, Redis for caching, and Stellar’s consensus protocol for transaction validation. This combination ensures that RendBit remains fast, reliable, and secure while processing cross-border payments at scale.

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Key Actors

RendBit’s system relies on a set of core actors to function effectively. Users interact with the platform to deposit, transfer, swap currencies, and manage wallets in a simple, fintech-like interface. They benefit from fast cross-border payments while blockchain settlement happens invisibly in the background.

Administrators oversee compliance, monitor transactions, and ensure that all operations follow regulatory and security guidelines. They are responsible for maintaining system integrity and responding to any anomalies.

Third-party service providers such as banks, payment gateways, and blockchain partners play a critical role in enabling on-ramps and off-ramps for fiat and cryptocurrency. Their collaboration ensures interoperability and smooth cross-border settlements across multiple financial ecosystems.

Continuous Data Availability, Even When Users Are Offline

RendBit ensures that users can initiate transactions even when internet connectivity is intermittent. Local caching, Redis in-memory storage, and queue-based message brokers allow deposits, transfers, and swaps to be queued and synchronized once connectivity is restored.

This approach guarantees that transactions are not lost and that data integrity is preserved, maintaining trust for users in regions with unreliable networks.

Offline support is fully integrated into the wallet interface, so users experience no disruption while performing critical financial operations, making cross-border payments more inclusive and reliable.

Exporting Keys

While RendBit is a custodial wallet by default, advanced users can export blockchain addresses and keys if desired. This enables direct on-chain activity, integration with external tools, or self-custody for tech-savvy users.

The feature is optional, ensuring that most users maintain a simple fintech experience without blockchain complexity.

All exported keys are encrypted and can be securely managed by the user, providing flexibility and transparency for advanced use cases.

Storage and Consensus

RendBit combines MongoDB for persistent storage, Redis for caching, and Stellar’s consensus protocol for transaction validation.

This hybrid approach ensures fast, reliable, and secure operations, supporting cross-border payments, currency swaps, and strict-send/strict-receive guarantees.

Data is encrypted at rest and in transit, with redundant storage to maintain availability and integrity across all nodes.

Integration Layer

The integration layer allows RendBit to connect seamlessly with third-party services such as CoinMarketCap, and LINKIO.

This enables fiat on-ramps, off-ramps, real-time crypto market data, and cross-platform interoperability without users needing to manage complex setups.

Developers and partner institutions can plug into RendBit’s APIs, leveraging compliance, KYC orchestration, and settlement infrastructure while focusing on building their own financial services.

Demo and Typical Usage

RendBit is typically used for cross-border payments, deposits, transfers, currency swaps, and merchant payments.

The demo showcases a smooth, fintech-like interface while blockchain handles settlement in the background. Users can initiate transactions, track balances, and receive notifications without ever needing to understand blockchain mechanics.

Advanced users can optionally access blockchain addresses or transaction proofs, giving them transparency and control while maintaining the simplicity of the platform for the general user base.

Technology Stack

Backend

RendBit uses Node.js with TypeScript for scalable backend services. MongoDB stores user data and transaction records, while Redis improves performance with in-memory caching. RabbitMQ handles asynchronous tasks and service communication.

Sensitive user data is encrypted with AES, passwords are hashed using bcrypt, and notifications are sent using Nodemailer. Secure login is enabled via Google OAuth and optionally strengthened with Google 2FA.

Frontend

The frontend is built with React.js and TypeScript, providing a fast, responsive interface. Vite is used as the build tool, Redux for state management, and Tailwind CSS for consistent, responsive design.

Infrastructure

RendBit is deployed on Nginx running on Ubuntu, with Docker for containerized environments. Cloudinary manages media assets, and GitHub handles version control. LINKIO provides on-ramp and off-ramp services for seamless fiat-crypto conversions.

Integrations

The platform integrates with Stellar Horizon for blockchain interactions, and CoinMarketCap for real-time crypto market data. Automated testing ensures stability, reliability, and compliance across the system.