Mostafa E.

🥇 Top Rated Plus (Top 3% on Upwork) ⭐ 5★ Rated by clients worldwide It has been over 5 years working professionally on Full-stack Engineering apps, and delivering end-to-end products for my clients. ✓ React & Next.js ✓ Node.js/Typescript (Express, NestJS) ✓ Python (FastAPI, Flask, Django) ✓ ReactNative Expo ✓ RAG Systems & Retrieval Optimization (pgvector, Pinecone, Qdrant, hybrid search, re-ranking, HyDE) ✓ AI Agents & Multi-Agent Systems (LangChain, LangGraph, CrewAI, AutoGen, ReAct) ✓ LLM Integration (Claude, GPT-4o, Gemini, Mistral, LLaMA) ✓ Voice AI (Vapi, Retell, 11Labs, Deepgram) ✓ Prompt Engineering, Chaining & Evaluation (RAGAS, LLM-as-judge) ✓ Agentic Workflow Automation (n8n, Zapier, Inngest) ✓ Long-Term Memory Systems (mem0, Zep) ✓ KV Cache Optimization & Context Window Management ✓ AI Observability & Tracing (Langfuse, LangSmith) ✓ Document Processing & Indexing Pipelines (OCR, chunking, structured extraction) ✓ NLP & Text Processing (classification, summarization, entity extraction, sentiment) ✓ Conversational AI & Chatbots ✓ Multi-modal AI (vision, audio, documents) ✓ Cost & Token Usage Optimization ✓ MCP (Model Context Protocol) Integrations ✓ PostgreSQL & MongoDB & Redis ✓ GraphQL & REST APIs ✓ AWS (EC2, Lambda, S3, SQS, DynamoDB) ✓ Azure ✓ Docker & CI/CD Pipelines