I’ve been experimenting with basic LLMs for small scripts, but I’m now planning to build a complex SaaS platform with a React frontend and a robust Node.js backend. I’m starting to hit a wall with context windows and keeping code consistent across multiple files. I really need an AI tool that can handle deep architectural logic and manage state across the entire application without losing the plot halfway through. I’ve looked into Cursor and GitHub Copilot, but I’m curious if there are better options for managing large-scale refactoring and API integrations. Which AI has the best 'reasoning' for complex project structures? I’d love to hear what you guys are actually using for professional-grade builds.