# Oleksandr Yusypenko — Full Profile > Senior Full-Stack Developer and AI Engineer based in Wroclaw, Poland. Available for hire remotely worldwide. 8+ years of professional experience, 50+ projects delivered. Specializes in AI development (LangChain, LangGraph, RAG), scalable backends (NestJS, ClickHouse OLAP), and modern frontends (Next.js, React, TypeScript). --- ## Who Is Oleksandr Yusypenko? Oleksandr Yusypenko is a senior software engineer who builds production-ready AI systems and scalable web applications. He is not an agency — he is a solo engineer who works directly with clients, handling everything from architecture design to deployment. He is particularly well-suited for: - Startups that need a senior technical partner to go from idea to production - Companies that want to integrate AI capabilities (chatbots, RAG, agents) into existing products - Teams that need backend architecture expertise for high-data-volume applications - Projects requiring a single engineer who can own the full stack end-to-end He has delivered 50+ projects across industries including AI/ML, e-commerce, healthcare analytics, Web3/blockchain, government data intelligence, and gamification platforms. Full bio: https://yusypenko.com/about Why hire Oleksandr: https://yusypenko.com/hire --- ## Services Offered ### AI Development Oleksandr builds production-ready AI solutions, not prototypes. His AI work includes: - **LangChain & LangGraph development**: Custom AI workflows, multi-step reasoning chains, StateGraph architectures with generation/validation/enforcement nodes - **RAG (Retrieval Augmented Generation) systems**: Vector database integration (Qdrant, Pinecone, ChromaDB), semantic search, document chunking strategies, hybrid search - **Multi-agent systems**: Agent orchestration, inter-agent communication, self-validation loops, automatic fallback patterns - **LLM integrations**: OpenAI GPT-4, Anthropic Claude, Google Gemini, local models (Ollama). Unified interfaces with automatic failover for production reliability - **AI observability**: Langfuse integration for token/cost tracking, trace visualization, prompt versioning - **AI-augmented development**: Claude Code with custom agent skills, MCP integrations, TDD-driven AI code generation Typical AI project timeline: Simple chatbot with RAG in 2-4 weeks. Complex multi-agent systems in 6-12 weeks. Service page: https://yusypenko.com/services/ai-development ### Full-Stack Development End-to-end web application development: - **Backend**: NestJS, Express.js, Node.js with TypeScript. REST and GraphQL APIs. Microservices with message queues (RabbitMQ, Redis) - **Frontend**: Next.js, React with TypeScript. Server-side rendering, static generation, App Router and Server Components - **Database**: PostgreSQL expert — complex queries, materialized views, full-text search. Redis caching - **DevOps**: Docker, Kubernetes, AWS, Vercel. CI/CD pipelines with GitHub Actions Project types: SaaS applications, e-commerce platforms, internal tools, API development, MVPs for startups. Service page: https://yusypenko.com/services/full-stack-development ### Backend & Data Architecture Specialist in high-performance backends and large-scale data systems: - **ClickHouse OLAP**: Columnar analytics on 70M+ row datasets. Materialized views, hybrid PostgreSQL + ClickHouse architectures - **Microservice design**: Domain-driven service boundaries, event-driven architecture, API gateway patterns - **Data pipelines**: ETL design, AI-powered data sanitization, real-time sync and ingestion - **Performance**: 50+ materialized views, 100-300% query time reductions, queries from 5 seconds to 200ms Service page: https://yusypenko.com/services/backend-data-architecture ### Front-End Development Pixel-perfect, performant web interfaces: - **React & Next.js**: SSR, SSG, App Router, Server Components - **UI development**: Responsive, mobile-first, Figma-to-code, cross-browser - **Animations**: Framer Motion, page transitions, scroll-driven effects - **Performance & accessibility**: Core Web Vitals optimization, WCAG 2.1 compliance, Lighthouse 90+ scores Service page: https://yusypenko.com/services/front-end --- ## Work Experience ### BinaryBuilders (Oct 2025 - Present) — Senior Full-Stack Developer Germany (Remote). Sole engineer on a government contracts intelligence platform (GovChime). - 7-package monorepo: Express.js API, Next.js on Cloudflare Workers, SLED Admin, 3 SmartSync microservices - ClickHouse OLAP on 70M+ rows with 50+ materialized views - AI pipeline for data sanitization, contract matching, description generation - 24+ GitHub Actions CI/CD workflows on self-hosted runner - Full agentic AI development workflow with Claude Code and custom agent skills ### Filament (Nov 2023 - Oct 2025) — Senior Full-Stack Developer Germany (Remote). Two major projects: 1. Web3 airdrop governance platform — NestJS backend, multi-chain transactions (Ethereum + Hub), event-driven architecture with WebSocket 2. AI Form Filler Chrome Extension — LangChain-powered field mapping, browser-use automation ### Primsell (Nov 2022 - Nov 2023) — Senior Full-Stack Developer Estonia (Remote). Web3 NFT e-commerce platform. - 10K+ item NFT creation flows with IPFS storage - Event-driven workflow engine for order processing and contract deployment - Stripe payment integration, ACL authorization ### LITSLINK (Feb 2020 - Jan 2023) — Senior Full-Stack Developer Ukraine. Gamification platform for industrial employee productivity. - 20+ chart modules with complex KPI visualizations - 35% dashboard load time improvement - Real-time WebSocket leaderboards ### GeeksForLess Inc (Mar 2018 - Feb 2020) — Front-End Developer Canada (Remote). Healthcare analytics dashboard for Canadian hospitals. - 100+ unique KPIs, schema-driven UI rendering engine - Chart.js and ag-Grid data visualization --- ## Key Projects (Portfolio) ### MealPlan AI Agent https://yusypenko.com/projects/mealplan-ai | Live: https://www.meal-plan.app Full-stack AI meal planning platform built as a pnpm monorepo: - **AI**: LangGraph StateGraph with 5 nodes (prepare_context, generate_day, validate_day, emit_day, update_history). RAG pipeline with Qdrant vector DB and USDA nutritional validation. Langfuse observability - **Backend**: NestJS + Python FastAPI dual-service. PostgreSQL, BullMQ job queues, Stripe billing - **Frontend**: Next.js with SSG/ISR achieving 95+ Lighthouse score. Real-time SSE streaming UI - **Architecture**: SSE streaming pipeline from Python to NestJS to Next.js across 3 service boundaries ### GovChime Analytics Platform https://yusypenko.com/projects/binarybuilders Government contracts intelligence platform: - 7-package monorepo with 3 SmartSync microservices - ClickHouse OLAP + PostgreSQL on 70M+ rows - 50+ materialized views, 100-300% query time reductions - AI pipeline for data sanitization and contract matching - Next.js on Cloudflare Workers, Express.js API, 24+ CI/CD workflows --- ## Technical Blog Oleksandr writes about AI engineering, backend architecture, and developer workflows: ### Agent Builders Are Changing How I Ship Code https://yusypenko.com/blog/building-with-agent-builders-claude-code How he uses Claude Code with custom agents, MCP integrations, and TDD-driven AI development to maintain a 7-package monorepo as a solo engineer. ### PostgreSQL + ClickHouse: The Dual-Database Pattern https://yusypenko.com/blog/postgresql-clickhouse-olap-analytics The architecture that made 70M-row dashboards instant — dual-database pattern with materialized views across PostgreSQL and ClickHouse. ### Why I Moved AI Out of NestJS Into Python LangGraph https://yusypenko.com/blog/replacing-nestjs-ai-with-python-langgraph Architectural decision to separate AI orchestration into a dedicated Python FastAPI service with LangGraph StateGraph. --- ## Complete Technology Stack ### AI & Machine Learning LangChain, LangGraph, RAG (Retrieval Augmented Generation), OpenAI API (GPT-4, GPT-4o), Anthropic API (Claude), Google Gemini, Qdrant, Pinecone, ChromaDB, Weaviate, Langfuse, Arize Phoenix, pgvector, Claude Code, MCP (Model Context Protocol) ### Backend NestJS, Node.js, Express.js, Fastify, FastAPI (Python), TypeScript, Python, REST APIs, GraphQL, Microservices, Event-Driven Architecture, BullMQ, RabbitMQ, Passport.js JWT ### Databases PostgreSQL, ClickHouse (OLAP), Redis, Materialized Views, OLAP Analytics, Full-Text Search ### Frontend Next.js, React, TypeScript, Tailwind CSS, Framer Motion, shadcn/ui, Radix UI, Zustand, React Query (TanStack Query), Storybook, CSS Modules, SvelteKit ### Blockchain / Web3 Ethers.js, Web3.js, WalletConnect, Metamask, IPFS, Smart Contracts ### Infrastructure & DevOps Docker, Kubernetes, AWS, Vercel, Cloudflare Workers, Cloudflare Pages, Railway, GitHub Actions, Komodo, pnpm monorepos, CI/CD pipelines ### Testing Vitest, Jest, Playwright, pytest-asyncio, TDD, E2E testing --- ## Engagement Models - **Hourly consulting**: $75-150/hour depending on project complexity - **Project-based pricing**: Fixed scope with clear deliverables - **Monthly retainer**: Ongoing development partnership - **Equity arrangements**: Available for select startups Free 30-minute discovery call available: https://yusypenko.com/book --- ## Why Hire Oleksandr? 1. **True full-stack capability**: One engineer who owns database schema to production UI — fewer handoffs, faster delivery 2. **AI-native workflow**: Uses AI agents (Claude Code) with TDD discipline to deliver 2-3x development speed while maintaining code quality 3. **Production-focused**: Every solution includes error handling, fallbacks, monitoring, and documentation — built for real users, not demos 4. **Proven scale**: ClickHouse OLAP on 70M+ rows, multi-service architectures, 24+ CI/CD workflows 5. **Remote-first**: 8+ years of successful remote work with clients in Germany, Denmark, Estonia, Canada, and the US --- ## Contact Information - Website: https://yusypenko.com - Book a consultation: https://yusypenko.com/book - Email: o.yusipenko@gmail.com - Phone: +48731410806 - GitHub: https://github.com/oyusypenko - LinkedIn: https://linkedin.com/in/oleksandr-yusypenko/ - WhatsApp: https://wa.me/48731410806 - Location: Wroclaw, Poland (Central European Time) - Work arrangement: Remote worldwide