Gregory Barmpas
Data Scientist | AI Engineer | Generative AI | LLM Applications | Time Series Forecasting
Data Scientist / AI Engineer with 4+ years of experience developing machine learning, demand forecasting, predictive analytics, and Generative AI solutions. Experienced in statistical modeling, ensemble learning, time-series forecasting, NLP, LLM applications, RAG systems, and production AI systems. Strong background in Python, SQL, scikit-learn, PyTorch, FastAPI, cloud technologies, and end-to-end AI solution delivery.
gregorybarbas@gmail.com | github.com/GregB712 | linkedin.com/in/gbarmpas
Experience
Data Scientist, Deus Ex Machina
Sep 2025 - Current
- Designed and deployed AI applications using OpenAI APIs, LangChain, FastAPI, and cloud-native architectures.
- Built Retrieval-Augmented Generation systems using embeddings, vector databases, and semantic search.
- Developed agentic workflows and AI assistants for information retrieval, document processing, and decision-support applications.
- Implemented NLP pipelines combining LLMs, clustering, classification, information extraction, and semantic retrieval.
- Collaborated with engineering teams to productionize AI solutions through APIs, containerization, and deployment workflows.
- Evaluated LLM performance using structured testing, prompt optimization, and retrieval quality metrics.
Data Scientist, Dataviva
Nov 2022 - Oct 2024
- Designed and optimized machine learning and statistical forecasting models for retail demand forecasting across large-scale product and store datasets.
- Developed predictive analytics solutions using ensemble learning and feature engineering to improve forecast accuracy.
- Built automated data pipelines for data preparation, model training, evaluation, forecasting, and reporting.
- Conducted model validation, backtesting, error analysis, and performance monitoring for reliable production forecasts.
- Led proof-of-concept initiatives and technical demonstrations for enterprise clients.
- Collaborated with stakeholders to translate business requirements into scalable AI and analytics solutions.
Application Consultant / Engineer, Veltio
Oct 2021 - Nov 2022
- Developed client-specific analytics and forecasting applications for supply chain optimization.
- Collaborated with business stakeholders to define requirements and translate operational challenges into data-driven solutions.
- Supported forecasting model implementation and deployment within customer environments.
- Participated in solution design, validation, and performance evaluation processes.
Skills
Machine Learning & Forecasting
Python, Pandas, NumPy, scikit-learn, XGBoost, LightGBM, Statistical Forecasting, Time-Series Analysis, Predictive Analytics, Ensemble Learning, Feature Engineering, Backtesting
Deep Learning & NLP
PyTorch, TensorFlow, Neural Networks, NLP, Sentence-BERT, Embeddings, Tokenization, Semantic Search
Generative AI
OpenAI API, LangChain, MCP, RAG, Prompt Engineering, Agentic AI, LLM Applications, AI Assistants, Information Retrieval, Document Processing
Data & Databases
SQL, MongoDB, PostgreSQL, Vector Databases, FAISS, Data Pipelines
Backend / MLOps / Cloud
FastAPI, Docker, Kubernetes, Git, CI/CD, AWS, API Development, Cloud-native AI Systems
Frontend / Full-stack
Next.js, React, TypeScript, Tailwind CSS, Prisma, Vercel
Languages
Greek: Mother tongue, English: C2 Certificate of Proficiency
Education
MSc Data and Web Science
School of Informatics | Aristotle University of Thessaloniki
Oct 2021 - Sep 2024
Erasmus+ Computer Science / Software Engineering
Malardalen University
Jan 2021 - Jun 2021
BSc Computer Science
School of Informatics | Aristotle University of Thessaloniki
Sep 2017 - Sep 2021