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Vitalii L
@vitalii_lysenko
Senior Backend and AI Engineer Python, RAG, FastAPI, Laravel, API
Ukraine
Ukrainien, Anglais
À propos de moi
Senior Backend & AI Engineer (8+ years). I bridge the gap between Modern AI and Enterprise Web.
🤖 AI & Python: I architect custom RAG microservices, LLM agents, and async systems using Python, FastAPI & pgvector. I build smart Corporate Knowledge Bases that eliminate hallucinations.
⚙️ Enterprise APIs: Deep expertise in PHP/Laravel, building high-load CRMs and complex integrations (Payments, Web3/TRC-20).
I design robust, scalable architectures from scratch. Let's build something great!
Compétences
Vitalii L
hors ligne •
Voir mes services
Correction de bugs
I will fix laravel bugs, 500 server errors, and database issues
Intégrations IA
I will build custom ai chatbot, rag system, and openai API integration
Portfolio
Expérience professionnelle
Senior AI Backend Engineer
Freelance • Freelance
Aug 2026 - Present • 2 mos
Designed and developed a production-ready Open-Source Corporate Knowledge Base (RAG microservice) from scratch. The engine functions as a smart search system, allowing AI to accurately answer questions based purely on internal corporate documentation. • Built a fully asynchronous architecture to ensure high throughput and low latency. • Implemented vector search using PostgreSQL with the pgvector extension for efficient document retrieval. • Engineered semantic query caching to significantly reduce OpenAI API costs. • Enforced strict context boundaries to guarantee zero LLM hallucinations. The core architecture is open-sourced to demonstrate code quality and system design. Link provided in my profile. Used technologies: Python, FastAPI, AsyncIO, PostgreSQL, pgvector, OpenAI API, Docker. The core architecture is open-sourced to demonstrate code quality and system design. GitHub Repository: https://github.com/VitaliiLysenkoo/rag-support-api Used technologies: Python, FastAPI, AsyncIO, PostgreSQL, pgvector, OpenAI API, Docker.
Senior Full Stack Engineer
Software Development • Temps plein
Dec 2022 - Jul 2026 • 3 yrs 7 mos
Developed complex CRM systems and REST APIs using Laravel 10 and Vue 3. Successfully integrated multiple third-party services and AI agents (OpenAI API) to automate business processes. Optimized database performance (MariaDB, Redis) for high-load workflows.
Backend Engineer
Software Development Company, Mobile App & Web Development Service • Temps plein
Nov 2022 - Nov 2023 • 1 yr
Built and optimized backend architectures for marketplaces. Designed secure REST APIs for React/Vue frontends. Key achievement: Integrated the Tron Network API to verify transactions, generate TRC-20 wallets, and process cryptocurrency payments seamlessly.
