I’m planning a new web application and need a seasoned full-stack partner to carry it from idea to launch. The core product will be a browser-based app, but I want it engineered responsively so users on both iOS and Android enjoy a native-like experience the moment they open it. I’m flexible on timeline—quality is more important than speed—so you’ll have room to make thoughtful architectural decisions. I expect you to handle everything from setting up the back-end (database design, APIs, authentication) through the front-end (modern JavaScript framework of your choice, clean component structure, mobile-first styling) and deployment to a cloud host. Please share links to previous web apps you built that behave flawlessly on mobile, and outline the tech stack you’d propose for this project. I’m especially interested in how you approach scalability, security, and cross-device testing. Together we’ll iterate on milestones, review features, and refine the UX until the app feels polished on every screen size.