Tamas – LLM, AWS, OpenAI, experts in Lemon.io

Tamas

From Germany (UTC-7)flag

Back-end Web Developer|Senior
AI Engineer|Senior

Tamas – LLM, AWS, OpenAI

Tamas is a Senior Back-End Engineer with 9+ years in software and a strong focus on Python, FastAPI and LLM/RAG systems. He has led AI projects end-to-end as a technical lead, including a multi-agent document intelligence system for a German government client and a production codebase assistant with version-aware, blue-green indexing. His delivery record includes concrete wins, such as cutting analytics latency by 50%. What sets him apart is a seasoned tech-lead mindset: he sets review standards for AI-generated code, mentors engineers, and steers clients toward workable compromises.

9 years of commercial experience in
AI
Data analytics
E-commerce
Fintech
Logistics
Supply chain
Enterprise software
SaaS
Main technologies
LLM
3 years
AWS
3 years
OpenAI
3 years
Python
5.5 years
Additional skills
Docker
PostgreSQL
Anthropic
AI agent development
Kubernetes
CI/CD
FastAPI
CrewAI
RAG
Direct hire
Possible
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Experience Highlights

AI / Full-Stack Engineer
Feb 2023 - Apr 20263 years 1 month
Project Overview

An AI assistant that lets engineers ask natural-language questions about a large, fast-changing codebase instead of digging through files and history by hand. It splits the code into chunks, embeds them in a vector store, and answers questions through an LLM over the retrieved code. It also supports queries against older versions of the repository.

Responsibilities:
  • Built and shipped the assistant end-to-end on a Python/FastAPI backend with a small OpenAI model; it ran in production for daily use by the engineering team.
  • Designed version-aware indexing pinned to commit SHAs, with tombstoning for deleted code, so queries about years-old versions still return accurate results.
  • Implemented blue-green index switching with atomic cutover, so a failed reindex never exposes partial data to users.
  • Replaced nightly rebuilds with incremental reindexing triggered from CI, re-processing only the files changed in each commit.
  • Chose WebSockets over REST for the indexing path to handle unpredictable indexing durations.
  • Defined retrieval evaluation (recall@k, precision, MRR) and per-request logging of chunk IDs, scores, index and model versions, and latency.
Project Tech stack:
Python
FastAPI
OpenAI
Vector Databases
WebSocket
CI
CD
AI / Full-Stack Engineer
Jan 2023 - Mar 20263 years 1 month
Project Overview

A document intelligence system for a German government organisation that had to process large volumes of mixed-format material by hand. It ingests text, scanned documents, images and video, extracts their content through OCR and multimodal pipelines, and lets staff search and query it in natural language. A multi-agent LLM layer routes each request to specialised agents for retrieval, extraction and answer generation. A fine-tuned small language model runs on a private server, so sensitive data never leaves the client’s infrastructure.

Responsibilities:
  • Led the system end-to-end as technical lead, from technology selection and resource planning through production rollout, observability and evaluation.
  • Designed the RAG and multi-agent architecture with LangChain and Pinecone, including ingestion pipelines for text, OCR’d scans, images and video.
  • Fine-tuned and deployed a small language model on private infrastructure to meet the client’s data-residency requirements.
  • Wrote the architecture and implementation documentation used for the client’s approval process.
  • Set coding guidelines, ran PR reviews of AI-generated code with a focus on design-level flaws, and mentored junior and senior engineers on the team.
Project Tech stack:
Python
FastAPI
AWS
OpenAI
Anthropic
LangChain
Docker
Kubernetes
Azure DevOps
CI
CD
PostgreSQL
pytest
LLM
AI agent development
Full-Stack Engineer
Jul 2020 - Dec 20222 years 5 months
Project Overview

A cryptocurrency platform serving both end users and internal operations teams. Resolving operational issues used to require manual API calls and direct database fixes. The platform includes customer-facing web applications, backend APIs, an internal approval portal, and admin tooling for data import/export, notifications and reporting.

Responsibilities:
  • Built a hybrid Python and Node.js backend with a maker-checker approval workflow, eliminating manual API calls and direct database interventions for operational issue resolution.
  • Developed production Next.js/TypeScript applications and reusable admin modules for data import/export, notifications and reporting.
  • Added traceable workflow state and kept roughly 80% Jest/Cypress branch coverage across critical flows, speeding up releases and debugging.
  • Coordinated API contracts and release dependencies across backend, frontend, QA and DevOps teams.
Project Tech stack:
Python
Node.js
Typescript
Next.js
Cypress
Full-Stack Engineer
Sep 2019 - Jul 202010 months
Project Overview

An internal operations platform for a national railway. Teams there managed daily tasks through manual, disconnected processes. It provides reporting dashboards, automated workflow notifications, and integrations that move operational data between enterprise systems.

Responsibilities:
  • Delivered API-connected data import/export, automated notifications and reporting dashboards, cutting manual operational work by more than 25%.
  • Built backend services in Java and C#/.NET plus integration pipelines connecting enterprise applications and operational data flows.
  • Developed React and Angular frontends for the dashboards and daily workflow tools.
Project Tech stack:
Java
C#
.NET
SQL
Full-Stack Engineer
Jun 2017 - Aug 20192 years 2 months
Project Overview

A suite of web applications for small and mid-sized businesses running online stores and day-to-day operations. It brings payments, storefront management, business tools and real-time sales analytics into one place.

Responsibilities:
  • Built real-time ETL/streaming pipelines that cut analytics latency by 50% across customer-facing products.
  • Integrated Stripe, PayPal, Shopify, Google Workspace and Office 365 APIs for payments, commerce and business workflows.
  • Shipped production Laravel/MySQL and Vue.js applications in a fully remote startup team.
  • Defined technical scope, timelines and integration requirements directly with project managers.
Project Tech stack:
PHP
Laravel
MySQL
JavaScript
Vue.js
Shopify
ETL

Education

2017
Computer Science
Bachelor of Science

Languages

German
Pre-intermediate
English
Advanced

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