About Zsombor
I'm a software engineer who builds production-grade AI — chatbots, agents, and automations that hold up with real users, not demos that break on day two.
Most "AI" freelancers are no-code resellers wrapping a prompt. I'm a computer science engineer (TU Delft, top 10%) who reads and writes the real code — so I can ground a chatbot in your data, stop it hallucinating, integrate it into your existing stack, and actually ship it to production.
What I build:
- Web/Mobile development — any kind of mobile/web platform with complex logic and database integration
- AI chatbots & RAG systems — trained on your own data, with citations and no hallucinations
- AI agents — tool-calling assistants that take real actions (bookings, lookups, CRM updates), plus MCP servers that connect AI to your tools
- AI voice agents — receptionists that answer calls 24/7 and book appointments
- Workflow automation — n8n, Make and Zapier flows that run your business on autopilot
- Fixing & finishing AI-built apps — taking Lovable / Bolt / Cursor MVPs the rest of the way to production
A few things I've shipped:
- An end-to-end RAG platform with inline citations and hallucination control (hybrid retrieval, reranking and a verification layer), grounded with Claude
- An AI code-review agent (LangChain / LangGraph) that cut manual PR review time by 80%
- A high-availability platform scaling to 6,000+ weekly active users
My stack: Python, TypeScript, React/Next.js, Node, FastAPI, LangChain/LangGraph, vector databases (Weaviate, pgvector), OpenAI & Claude, n8n / Make, AWS & Azure, Docker.
How I work: I scope honestly, explain things in plain English, test before I deliver, and hand over clean, documented work that you own. If something can't be done well, I'll tell you — and propose what can.
Message me with what you're trying to build, and I'll tell you exactly how I'd approach it.
English
Native or bilingual
Hungarian
Native or bilingual
Remote only
Primarily works remotely
Experience
- Amazon Web ServicesSoftware Development Engineer InternMay 2026 - Today (1 month)Dublin, Ireland– Incoming SDE intern on the Amazon DynamoDB team, contributing to the distributed systems and infrastructure behind AWS's fully managed NoSQL database, which serves single-digit-millisecond performance at global scale.
- AltixArtificial Intelligence Engineer InternApril 2026 - Today (2 months)Amsterdam, Netherlands
- Designed an end-to-end RAG pipeline (query rewriting, classification/routing, retrieval, streaming answer generation, and citation resolution) grounded with Claude, producing structured output with inline citations resolved to source document, page, and excerpt.
- Built hybrid retrieval over a Weaviate vector database, fusing semantic and keyword (BM25) search with Reciprocal Rank Fusion and a cross-encoder reranker.
- Implemented hallucination prevention via a verification model with confidence scoring, plus a Redis semantic caching layer to cut latency and cost on repeat queries across strictly isolated multi-tenant data.
- Virtual Front DeskSoftware EngineerDecember 2022 - Today (3 years and 6 months)
- Spearheaded a team of 4 to architect a high-availability video calling platform, scaling to 6,000+ Weekly Active Users (WAU).
- Engineered scalable RESTful services using Express.js and Azure, optimizing server-side logic to achieve a 15% reduction in API latency.
- Caught regressions before release by single-handedly building a Playwright end-to-end testing suite wired into full CI/CD, running automatically on each commit
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Education
- Bachelors Degree in Computer ScienceDelft University Of TechnologyCoursework: Machine Learning, Data Structures, Algorithms, Databases, Networks, Linear Algebra.