Built a full-stack ISP Management and Billing System from the ground up — a multi-role SaaS-ready CRM designed for internet service providers managing dealers, customers, and network infrastructure at scale.

Core features include a real-time dealer credit ledger with hard-reject logic, automated nightly customer suspension tied to package expiry, PPPoE credential generation on activation, and PDF invoice generation on every transaction. The system is architected with a shared PostgreSQL database serving both the application layer and FreeRADIUS — meaning network-level actions like customer suspension and bandwidth enforcement flow directly from CRM operations without any manual intervention.