Senior Backend Engineer (Node.js / TypeScript / AI)

*Job Description:* Senior Backend Engineer (Node.js / TypeScript / AI) Location: [Remote / On-site / Hybrid] Job Type: Full-time Experience Level: Senior (5+ years) *About the Role* We are looking for a highly skilled Senior Backend Engineer to lead the development of a modern, data-driven analytics and AI chat platform. You will be responsible for building robust, scalable APIs, managing real-time database architecture, and integrating sophisticated AI (Large Language Model) pipelines. In this role, you will tackle complex data aggregation challenges, implement secure authentication systems, and build Retrieval-Augmented Generation (RAG) pipelines that power intelligent, deterministic AI chatbot features. *Key Responsibilities* - API Development: Design, build, and maintain high-performance RESTful APIs using Node.js, Express.js (v5), and strict TypeScript. - ⁠Database & Architecture: Architect and optimize schemas, indexes, and complex data aggregation queries using real-time backend-as-a-service (BaaS) platforms (e.g., Convex). - ⁠AI Integration: Develop and maintain advanced AI pipelines, integrating LLMs (e.g., OpenAI API) with vector databases for semantic search, query classification, and dynamic prompt generation. - ⁠Security & Compliance: Implement and maintain robust security protocols, including JWT-based authentication, Role-Based Access Control (RBAC), rate limiting, and comprehensive vulnerability mitigations. - ⁠Data Processing: Build and maintain scalable data ingestion pipelines, handling large-scale bulk imports, data sanitization, and fuzzy matching. - ⁠Quality & Testing: Write clean, maintainable code with high test coverage using tools like Jest and Supertest. Lead code reviews and drive engineering best practices. - ⁠Mentorship: Mentor junior and mid-level engineers, fostering a culture of technical excellence and continuous improvement. *Required Qualifications* - Experience: 5+ years of professional backend software development experience. - ⁠Core Languages & Frameworks: Deep expertise in Node.js (v20+) and TypeScript (strict mode, advanced types). Extensive experience with Express.js. - ⁠Database Mastery: Strong background in designing database schemas, writing complex aggregations, and optimizing queries. Experience with modern real-time platforms or serverless databases (e.g., Convex, Supabase, or Firebase) is highly preferred. - ⁠AI/ML Familiarity: Proven experience integrating LLM APIs (OpenAI), working with text embeddings, vector similarity search (cosine similarity), and building RAG applications. - ⁠Security: Solid understanding of web security fundamentals, JWT lifecycle management, password hashing (bcrypt), CORS, and OWASP top 10 vulnerabilities. - ⁠Testing: Strong experience with unit and integration testing frameworks (Jest). - ⁠Tools & Operations: Experience with Git, CI/CD pipelines, structured logging (e.g., Pino), and modern development workflows. *Nice to Have* - Experience migrating or maintaining hybrid auth systems (e.g., Clerk + custom JWT). - ⁠Familiarity with algorithmic data processing, string similarity algorithms (Levenshtein distance), and data normalization. - ⁠Experience with file parsing and document text extraction (e.g., PDF processing). - ⁠A background in building data-heavy compliance, reg-tech, or fintech applications.