Muhammad Ehsan N.

Senior Backend & AI Engineer | Node.js | PostgreSQL | RAG & LLMs

AVAILABLE NOW! I’m Muhammad Ehsan Nissar, a Senior Backend & AI Engineer with 7+ years of experience building high-performance, scalable, and secure SaaS platforms. I specialize in Node.js (NestJS, ExpressJS, Loopback), PostgreSQL, MongoDB, and AWS Cloud Infrastructure, along with advanced AI system design — including LLM integrations, RAG pipelines, vector search, and fine-tuning AI models. I’ve built multi-tenant systems, chatbot analytics platforms, and AI-powered automation backends — integrating with OpenAI, CRMs, Stripe, Modern Treasury, Plaid, and more. My solutions have powered production environments serving thousands of users and delivered measurable results, such as reducing reporting time by 98% and lowering cloud costs by 40%. 🧠 What I Do Best Backend Engineering 🏗 Design & Develop highly scalable REST APIs for SaaS platforms, AI systems, fintech products & chatbots 💾 Architect clean, optimized database schemas (PostgreSQL, MongoDB) 🔒 Build secure systems with JWT, RBAC, encryption, and audit logging 📈 Integrate 3rd-party APIs like OpenAI, Stripe, HubSpot, Twilio, Modern Treasury, Plaid, etc. 🧩 Deliver clean, testable, production-grade code following best practices AI & LLM Engineering 🤖 Build AI-powered backends & automation workflows 📚 Implement RAG pipelines using vector databases (Pinecone, Elastic, MongoDB Atlas Search, etc.) 🧠 Fine-tune LLMs & deploy custom AI models 🔎 Build embeddings-based search, document ingestion pipelines, and chat workflows ⚡ Integrate OpenAI, Anthropic, and other LLM providers into existing systems 📊 Create analytics pipelines for chatbot performance, agent assist, and real-time AI insights Cloud & DevOps ☁️ Deploy and scale backend systems using AWS (ECS, Lambda, S3, CloudFormation, CDK) 🐳 Containerize applications with Docker 🔧 Automate CI/CD with GitHub Actions 📬 Build event-driven architectures using RabbitMQ, Kafka, or SQS ⚙️ Tech Stack Languages: JavaScript, TypeScript, C++, Java Frameworks: NestJS, ExpressJS, LoopbackJS, Angular, NextJS Databases: PostgreSQL, MongoDB AI: OpenAI APIs, LLM Fine-tuning, Vector Databases, RAG Pipelines Cloud & DevOps: AWS (ECS, S3, RDS, Lambda, CDK), Docker, GitHub Actions Messaging: RabbitMQ, Kafka Architecture: Event-Driven, Microservices, SOA, Serverless 💬 Why Clients Hire Me ✅ Proven track record delivering complex backend and AI systems ✅ Strong understanding of scalability, performance tuning, and cloud cost optimization ✅ Excellent communicator — professional documentation, clean code, strong testing discipline ✅ Long-term thinker — I focus on reliability, maintainability, and future-proof design If you’re building a modern SaaS platform, fintech product, AI automation system, or chatbot backend, let’s talk. I’ll help you design a backend that’s fast, secure, and ready to scale — powered by the latest in AI and cloud technology 🚀