Corona y CIA - Accounting Firm Management System

Corona y CIA needed to move away from spreadsheets & manual tracking to manage its accounting clients' tax compliance obligations. I designed & built this system from scratch on a custom, frameworkless PHP MVC architecture, no Laravel or Symfony, just clean separation between models, controllers & views.

The system centralizes each client's FIEL (Mexican digital tax signature) files & passwords, ingests their official Constancia de Situación Fiscal PDF from the SAT, and auto-parses it (via smalot/pdfparser) against a configurable catalog to determine which monthly tax obligations apply.

Every month, the system auto-generates the collections (cobranza) workload per client, tracks fee & obligation status, parses uploaded payment receipts to auto-apply them, and sends account-statement PDFs (dompdf) to clients via a secure, token-protected public link, no login required on their end. Role-based user management & PHPMailer-driven notifications round out the day-to-day operation for the firm's staff.

Under the hood: PHP 8, Composer/PSR-4 autoloading, and PDO throughout, with prepared statements binding every user-supplied value. This one belongs squarely in Systems & Apps: it's not a demo, it's the actual system the firm's staff run their billing & compliance workload on every month.