Zero-Cost S3-Compatible Storage: Repurposing Idle Personal Cloud Accounts as Enterprise Object Storage

Developers often struggle with prohibitive cloud storage costs when scaling personal projects and microservices. This architectural blueprint transforms unused space in personal cloud accounts (Google Drive, Dropbox, Mega) into a fully functional S3-compatible object storage system at zero cost by implementing a stateless, stream-first design. By combining NestJS, Fastify, and OpenDAL within a monorepo structure, the solution achieves enterprise-grade performance and security while eliminating infrastructure expenses entirely.