Oleg — Backend Development freelancer in Beersheba

I build production B2B SaaS with AI at the core. One engineer who owns the full stack — frontend, backend, infra, and the AI itself. Selected production work: VendorFox (vendorfox.ai) — B2B SaaS for Managed Service Providers. Tracks hardware lifecycle, firmware, and security advisories across 48+ vendors. Backend is a graph-driven LLM orchestration engine: DAG execution, three-tier cascading scope, five layers of dedup with atomic locks to eliminate redundant LLM spend, automatic catch-up for failed cascades. Next.js + TypeScript frontend, FastAPI + Node.js backend, Firebase Auth, Firestore, Stripe billing (four tiers), Elasticsearch search, HubSpot CRM, CMDB integrations, multi-tenant dashboards. Live, paying customers. DataAbyss (app.dataabyss.ai) — OSINT intelligence platform used by government and national security professionals. Elasticsearch across billions of entity connections, NLP-powered data processing, RAG pipelines, LLM-powered chat interface, D3 visualizations, real-time analytics. Won a Gold Stevie Award for Achievement in Science or Technology at the 2023 American Business Awards. What I build: Production LLM orchestration: structured outputs, prompt dependency graphs, retry logic, cost control that keeps API bills predictable RAG pipelines with real retrieval performance tuning Vector search on PostgreSQL (pgvector) and dedicated vector DBs (Pinecone) Multi-tenant B2B SaaS with Stripe billing, Firebase Auth, Cloud Run deployment Distributed agent workflows with concurrency control and fault tolerance Stack: Next.js, TypeScript, FastAPI, Python, Node.js, PostgreSQL, Elasticsearch, Firebase, Firestore, AWS, GCP, Cloud Run, Docker, LangChain, Claude, OpenAI, Stripe. Background: First-class Physics degree, 4.0 GPA (Open University UK).