CQR Vault

The product

CQR Vault is a digital-asset platform that combines cryptocurrency wallet functionality with buying, selling, trading, and transfer flows for precious-metal assets, including gold and silver. The product brought wallet functionality, asset transactions, marketplace features, live metal prices, member communication, and administration into one experience spanning mobile and web.

My work

I built CQR Vault from the ground up as a full-stack/core developer at KryptoMind, taking ownership across the mobile application, backend, web interface, and administration tools. My work covered application architecture, blockchain integrations, wallet functionality, security features, deployment, and Android publication on Google Play.

Cryptocurrency wallet and blockchain integration

The wallet supported functionality involving Bitcoin, Ethereum, and Binance Smart Chain. I integrated blockchain functionality into the broader product experience, covering asset management, transfers, and the interfaces users needed to interact with their holdings. Web3.js was part of the stack for EVM-compatible blockchain functionality.

Precious-metal assets and marketplace

Alongside cryptocurrency, CQR Vault supported digital-asset functionality associated with precious metals, including gold and silver. The platform included buying, selling, trading, and transferring these assets, with marketplace features for presenting available listings. The application needed to communicate the relevant asset information and transaction actions clearly across both asset categories.

Live metal prices

CQR Vault integrated live precious-metal pricing so users could access current market-rate information within the application. This required connecting external pricing information to the asset screens and keeping displayed data relevant to user activity.

Mobile application

I independently developed the React Native mobile application, covering application structure, interface, navigation, state management, integrations, and release process. The mobile work included:

• Wallet and asset-management interfaces.
• Cryptocurrency and precious-metal transaction flows.
• Marketplace functionality.
• Live metal-price information.
• Biometric authentication.
• Secure key management.
• Push notifications.
• Mobile performance optimization.
• Android and iOS interfaces.

I used Redux for application state management, owned the navigation architecture, and handled Android deployment and Google Play publication.

Security, communication, and notifications

Security was significant because the application involved wallet access and digital assets. My work included secure key management and biometric authentication alongside protected wallet interactions. The platform also included real-time member chat and push notifications.

Backend, web, and administration

I designed and developed the backend using NestJS and MongoDB. The React-based web interface provided another way to access the platform, while the Next.js and Material UI administration dashboard supported internal management and operational workflows. I coordinated these interfaces with shared backend services and consistent product behavior.

Technical architecture and stack

Key engineering challenges

The project combined mobile interfaces, backend services, blockchain interactions, external pricing data, and operational tools. Wallet functionality and asset transactions needed to fit naturally into the application while accounting for underlying blockchain behavior. The mobile application required careful handling of sensitive wallet information, biometric access, application state, and performance. Supporting cryptocurrency and precious-metal assets also required appropriate data and actions for both categories within one consistent product.

Links and status

CQR Vault remains represented by the website and Android listing shown in the links above. The page describes my reported implementation scope and does not present security, asset-backing, returns, or transaction-performance claims as an independent audit.