Experienced website developer Needed, modify react nodejs AI related features

We are seeking an elite, senior-level Full-Stack Developer to modify core features, optimize data pipelines, and patch mission-critical backend errors within our enterprise SaaS dashboard. ​This is a highly urgent project with a Fixed Price and a Single Milestone. The entire scope must be refactored, tested, and deployed to production within 2 days (48 hours). If you have deep experience handling high-throughput enterprise architectures, secure payment workflows, and production-grade AI implementations under pressure, we want to hire you immediately. ​ Required Skills & Tech Stack: ​Applicants must have verifiable expertise in the following enterprise-grade technology stack: ​Frontend Architecture: React, Next.js, JavaScript (ES6+), WebSockets (for real-time dashboard data streams). ​Backend & API Orchestration: Node.js, ExpressJS, API Development, GraphQL, WebSockets. ​Database, Caching & Vector Storage: MongoDB, PostgreSQL, Redis (Enterprise Caching/Session Management), and Vector Databases (for enterprise LLM embeddings/RAG pipelines). ​AI Implementation & Data Science: Python, AI Automation / Agentic implementation (LangChain, LLM API architectures). ​DevOps, Cloud & Version Control: Docker (Containerization), Amazon Web Services (AWS), GitHub (Advanced Git workflows). ​Enterprise Feature Modification Tasks: ​The successful freelancer will be responsible for modifying and optimizing the following enterprise-level features: ​AI Implementation & Vector Query Optimization: ​Modify and refine our existing enterprise AI features, focusing on optimizing high-latency vector database queries. ​Enhance the Python/Node.js bridge to streamline asynchronous data processing and reduce response times for AI-driven insights on the dashboard. ​Data Synchronization & Caching Layers: ​Optimize our data pipeline connectors to ensure real-time analytics sync smoothly across the user interface via WebSockets. ​Implement robust Redis caching strategies to decrease database load and prevent frontend rendering delays (NaN or empty states) during high traffic. ​Role-Based Access Control (RBAC) & Audit Logging: ​Modify existing authorization middleware to ensure strict enterprise data isolation across different user roles. ​Validate that all backend payment and AI configurations are securely locked behind appropriate OAuth 2.0/token validation layers. ​Project Timeline & Terms: ​Urgency: High. Immediate start; final delivery within 48 hours. ​Budget: Fixed Price. ​Milestones: Exactly 1 Milestone (100% funds released upon final verification of a fully working live system). ​Security: Staging/sandbox environments and dummy environment variables (.env) will be provided for isolated testing. No direct production credentials will be shared. ​How to Apply: ​Please submit a concise proposal addressing the following: ​Briefly highlight an enterprise-level MERN/Next.js application or complex AI/vector pipeline you have modified. ​Confirm that you can clear your schedule to deliver this patch within our strict 2-day fixed window. ​Include the phrase "ENTERPRISE_MERN_AI" at the very top of your proposal so we know you possess the senior-level technical depth required for this project.