Legacy PHP to NestJS Portal Migration

A small web agency wanted to modernize their internal customer portal that they'd been using for 3 years. It was built in PHP and worked fine, but they wanted to rebuild it with their current tech stack (Node.js) so their developers could maintain it more easily. The portal handled customer login, invoice viewing, and support tickets for about 80-100 active clients.

I rebuilt the portal in NestJS over 5 weeks:

Mapped out the existing features - authentication, invoice display, ticket system, and file uploads

Set up NestJS with TypeScript and connected to their existing MySQL database (didn't want to migrate data)

Built REST APIs for each feature, starting with authentication

Implemented JWT-based login to replace their old session system

Added validation using class-validator since the old version barely had any

Wrote the ticket submission and file upload endpoints

Tested everything against their staging environment

Deployed and monitored for the first few days to catch any issues

NestJS, TypeScript, MySQL, JWT, Multer for file uploads

Migration completed in 5 weeks working part-time

Portal now runs on the same stack as their other projects

Their team can now maintain and update it without context switching

Fixed some edge cases in form validation that occasionally caused issues

Added better error messages that help their support team troubleshoot faster

System handles their current load without issues