Engineered Next.js & PostgreSQL booking and subscription systems powering 2,000+ bookings and 600+ sales, with automated iPAY checkout, Oblio e-invoicing, asynchronous Resend emails, and real-time Telegram alerts.

In-memory Go database built over raw TCP sockets handling connection lifecycles and custom text protocols, with thread-safe sync.RWMutex concurrent state management and file I/O data recovery.

Concurrent Go CLI engineered using worker pools, channels, and WaitGroups for high-throughput parallel website health checks.