PHP 8.1 Server Upgrade

My production server is still running PHP 7.x and I’m ready to move it to PHP 8.1. The box hosts only a set of custom-built PHP scripts—no WordPress, Laravel, or other frameworks—so the upgrade mainly needs to preserve the behaviour of those bespoke apps.

I need someone who can:

• Back up the current PHP configuration and any critical ini files
• Install and enable PHP 8.1 side-by-side or in place, depending on best practice for minimal downtime
• Re-apply existing modules/extensions (pdo_mysql, mbstring, gd, etc.) in their PHP 8.1 compatible versions
• Test the custom scripts for deprecation warnings, strict-type issues, or other breaking changes, and resolve anything uncovered
• Roll back quickly if an unexpected issue appears after go-live

Success is a clean upgrade with the custom scripts running error-free under PHP 8.1, verified via the web interface and CLI.