About

We have our own VPN client for Windows. We need to implement subscription payments via cryptocurrencies (Bitcoin, Ethereum, USDT, etc.). Only a ready-to-use Windows version of the client is available; source code and documentation are not available. It can be used as a reference for analysis and logic development. Main tasks: Analyze the current client's performance (reverse engineering or behavior analysis). Design and implement a crypto payment module. Configure integration with crypto processing (e.g., Coinbase Commerce, Binance Pay, BTCPay Server, or your own solution). Implement the logic for activating and renewing subscriptions after payment confirmation. Ensure security (keys, tokens, data transfer, protection against counterfeiting). Requirements: Experience with cryptocurrency APIs and payment gateways. Understanding of licensing and subscription management principles. Ability to work without documentation and restore logic based on the finished product. Willingness to take on the entire development cycle: from architecture to launch.