Valentyn S.

I help startups and B2B SaaS companies build, ship, and scale complete web applications powered by production-grade AI. Instead of hiring separate frontend, backend, and AI infrastructure engineers, I handle the entire product lifecycle — bridging the gap between robust, scalable full-stack architecture (NextJS, NodeJS, Python, AWS) and cutting-edge GenAI implementations (RAG pipelines, autonomous agents, and LLM orchestration). With 10+ years in full-stack development, $200K+ earned on Upwork, and a 100% Job Success Score (Top Rated Plus), I build with an ownership mindset to ensure your MVP hits the market fast and scales smoothly. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🌐 FULL-STACK & AI CAPABILITIES — WHAT I BUILD ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ → Full-Stack SaaS Platforms: Complete web applications with responsive UIs, secure multi-tenant auth, and complex business logic (React, NextJS, TypeScript). → AI Agents & Agentic Workflows: Multi-agent systems capable of autonomous execution, tool usage, and function calling (OpenAI, Claude, Gemini). → Production RAG Pipelines: Enterprise semantic search utilizing vector databases (Pinecone, pgvector, Qdrant) for accurate, private data querying. → Robust Backends & APIs: Highly performant, clean-code REST/GraphQL APIs and microservices (NodeJS, NestJS, Python, Express). → Automated Business Workflows: Intelligent document processing, automated lead scoring, and custom CRM/ERP AI integrations. INDUSTRIES I SERVE WITH AI + WEB SOLUTIONS: - Multifamily Real Estate — Custom web software layered over Yardi, AppFolio, Entrata, ResMan, RealPage, Apartments com - Hospitality / Hotels / Restaurants — AI booking flows, guest communication platforms, and review automation dashboards - MarTech / AdTech — Complete web analytics suites integrated with AdTech and MarTech API, and others like Meta, Google, TikTok, Yelp, and UberEats APIs ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🏆 RESULTS FROM RECENT PROJECTS ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✔ AI Voice Agent SaaS Platform — Complete frontend UI/UX redesign + Supabase backend refactor, delivered in 90 days ($7,000 fixed price, 5.0 ★) ✔ Senior NodeJS SaaS Integration — 816 hours of self-driven backend delivery on schedule across 6 months ($32,633, 5.0 ★) ✔ AI-Powered Real Estate Onboarding — Built the web frontend and AI backend workflow that reduced onboarding drop-off and boosted conversions. ✔ Enterprise Software — Systems built by my team are used daily by Cushman & Wakefield (Fortune 500 real estate firm). ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚙️ TECH STACK ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ AI / LLM Integration: OpenAI API, Claude API, Gemini, LangChain, RAG, Vector Databases, Prompt Engineering, Function Calling, Structured Outputs Backend Development: Nodejs, NestJS, Python, Expressjs, Nextjs (Server Components) Frontend Development: React, TypeScript, Redux, Nextjs, Material UI, Tailwind CSS Mobile App Development: Flutter (Cross-platform, CI/CD with Codemagic) Cloud & DevOps: AWS (SQS, SNS, Lambda, RDS, ECS, ECR, CloudWatch, EventBridge, VPC, Route53, EC2), Terraform (IaC), Docker, Docker Swarm, Nginx Databases & Caching: PostgreSQL, MongoDB, MySQL, Redis, Pinecone, Qdrant, pgvector API & Enterprise Integrations (50+ types): REST / GraphQL / SOAP · OAuth2 / OIDC · Webhooks · ETL Pipelines · Payload Encryption ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🏢 ENTERPRISE & THIRD-PARTY INTEGRATIONS ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Property Management Systems (PMS): Yardi Voyager · AppFolio · Entrata · ResMan · RealPage · Apartments com Marketing & Social Platforms: Meta (FB/IG) · Google Suite · Twitter/X · TikTok · Yelp · UberEats Past Enterprise Client Impact: STIHL · Liebherr · Cushman & Wakefield ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🤝 HOW WE WORK TOGETHER ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ → Discovery call → System architecture proposal → Milestone-based delivery → MVP in 6–12 weeks, production-ready scaling in 18–32 weeks → Available 30+ hrs/week, response time within 4–8 hours → Backed by a distributed team across 🇺🇦 🇵🇱 🇮🇹 🇷🇴 🇨🇦 if you need to scale resources rapidly I prioritize long-term, high-trust partnerships over quick fixes — 29 completed projects with an average engagement of 12-24 months. Let's jump on a call and map out what you're building.