Where PHP Still Wins
Anything touching Magento, WordPress, or the broader PHP ecommerce/CMS ecosystem — PHP isn't legacy there, it's the native language of the platform. Laravel has also made modern PHP a genuinely pleasant, productive framework for general backend work, not just legacy maintenance.
Where Node.js Tends to Win
Real-time features (websockets, streaming), a team already writing JavaScript/TypeScript on the frontend that wants one language across the stack, and I/O-heavy services where Node's non-blocking model fits naturally — like the streaming AI chat pattern used in ZaidanLab's own open-source Cloudflare Workers template.
The Question That Actually Decides It
What does the project need to integrate with, and what does the team already know well? A greenfield SaaS with a React frontend and no ecommerce-platform dependency leans Node; anything built on or integrating deeply with Magento leans PHP. Language choice driven by the actual integration surface, not trend, is what keeps a project maintainable two years in.