ResumeLM is an AI-powered resume builder application built with Next.js 15, React 19, and TypeScript. It provides a SaaS platform for creating, editing, and optimizing resumes for tech job applications, featuring AI-assisted content generation, resume tailoring for specific job applications, ATS optimization, and cover letter generation. The application uses Supabase for authentication and data storage, Stripe for subscription management, and integrates with multiple AI providers (OpenAI, Anthropic, Google, etc.) via OpenRouter or direct API keys. The architecture follows a modular structure with separate concerns for authentication, dashboard, resume editor, admin panel, and settings, leveraging server actions for data mutations and a robust AI abstraction layer for model selection and usage tracking.