Stas H.

Building an AI feature is easy. Making it reliable, scalable, and useful in a real product is where engineering matters. I work at the intersection of Python Backend, AI Engineering, and FinTech — building everything from production APIs and payment systems to LLM agents, RAG applications, and real-time voice assistants. My focus is not just writing code. It's understanding how a product should work, choosing the right architecture, and building systems that can grow without becoming difficult to maintain. What I've worked on: • FinTech & Crypto — Backend development for transaction-heavy financial applications, including payment processing, blockchain integrations, asynchronous workflows, idempotency, and data consistency. • AI Agents & LLM Applications — AI-powered features using OpenAI, Anthropic Claude, and Gemini. Multi-step agent workflows, tool/function calling, structured outputs, RAG, embeddings, and vector search. • Real-time Voice AI — Conversational voice assistants built with LiveKit, Deepgram, and ElevenLabs, combining speech-to-text, LLM processing, text-to-speech, and real-time audio streaming. • AI Automation — Business workflow automation using n8n, Make (Integromat), Python, and external APIs. Data enrichment, web scraping, background processing, and automated integrations. • Backend & SaaS — Python APIs, database design, third-party integrations, asynchronous processing, performance optimization, and backend architecture for web applications and MVPs. How I can help: - Build a Python backend or SaaS MVP from scratch - Develop AI agents, RAG systems, and LLM-powered applications - Integrate OpenAI, Claude, or Gemini into an existing product - Build real-time AI voice assistants and conversational systems - Automate business processes with n8n, Make, or Python - Implement payment systems, subscriptions, and FinTech integrations - Improve, refactor, or scale an existing backend - Take ownership of a complex feature from architecture to production Tech stack: Backend: Python, FastAPI, Django, DRF, PostgreSQL, Redis, SQLAlchemy, Celery, asyncio, REST APIs, WebSockets AI & LLM: OpenAI, Anthropic Claude, Gemini, LangChain, LangGraph, OpenAI Agents SDK, RAG, pgvector, embeddings, vector search, AI agents Voice AI: LiveKit, Deepgram, ElevenLabs, STT/TTS, real-time audio Automation: n8n, Make (Integromat), API integrations, webhooks, web scraping, data pipelines Infrastructure: AWS, GCP, Docker, Linux, Nginx, CI/CD, Supabase FinTech: Stripe, payment APIs, subscription billing, blockchain, Web3 Frontend when needed: React, Next.js, JavaScript, TypeScript How I work: I prefer straightforward solutions over unnecessary complexity. If something can be built with a clean API and a background worker, I won't recommend five microservices just to make the architecture look impressive. I can work independently, join an existing engineering team, or help turn an early-stage idea into a production-ready product. If you're building something involving Python, AI, automation, or FinTech, tell me what you're working on and what challenges you're facing. I'll be happy to discuss how I can help.