Stylianos Papargyris

Data Scientist | AI & Machine Learning | Weather AI, Climate & Earth Observation

Stylianos (Stelios) Papargyris

Thessaloniki, Greece

Available — Open to new roles

Data Scientist at the intersection of AI, weather, earth observation, and environmental data. I design and build systems that turn complex geospatial and atmospheric data into decisions — from ECMWF ensemble post-processing to real-time precipitation nowcasting across Europe. Currently seeking roles in applied ML, weather AI, or climate tech.

Live Platform — Operational 24/7 precipiteau.com

Precipiteau

Owner

A fully self-built, operational European precipitation platform covering 35+ countries, running 24/7. Delivers five distinct data products on a single interactive map: live radar rain-rate (EUMETNET OPERA), radar–satellite fusion (H-SAF MSG/SEVIRI fill-in), daily accumulation, raw reflectivity (ZhMax in dBZ), and a 1-hour optical-flow nowcast — every layer auto-refreshed every 15 minutes.

Custom-implements the Ramer ice-fraction algorithm against DWD ICON-EU vertical profiles downscaled to a 1 km terrain DEM, diagnosing precipitation phase (rain, snow, freezing rain, ice pellets, hail) across the full European domain. GPU-accelerated rendering with adaptive preloading for smooth animation on any device.

Open platform →
Coverage
35+ European countries
Update frequency
Every 15 minutes
Data sources
OPERA · ICON-EU · H-SAF
Nowcast horizon
60 min ahead
Stack
FastAPI · Leaflet · Python
Jan 2025
Now
WeatherXM
Weather Data Scientist
  • Designed and deployed a production XGBoost pipeline that bias-corrects ECMWF 51-member seasonal ensemble forecasts against ERA5 reanalysis across 14+ global regions — achieving +52% HSS improvement for precipitation and 30–50% RMSE reduction for temperature, with RMSE reductions of 25–29% across wind speed, humidity, and pressure; data ingested via Copernicus CDS and outputs delivered to AWS S3.
  • Designed and deployed an automated parametric insurance resolution system for ParahubXM (WeatherXM's parametric insurance platform), processing ERA5 climate reanalysis to classify risk and resolve contracts across travel insurance and crop/farmer protection use cases via threshold-based precipitation analysis.
  • Contributed feature additions and bug fixes to the Quality of Data (QoD) pipeline, including integrating ISD model scores into the QoD scoring logic and resolving edge cases in the MLflow and batch inference pipelines.
  • Built a comprehensive automated pytest suite for the Quality of Forecasts (QoF) pipeline, covering forecast evaluation, meteorology utilities, observation processing, and data transformer modules — with fixture datasets for reproducible testing.
Machine LearningERA5ECMWFXGBoost Ensemble post-processingnetCDF / xarray
Oct 2023
Jan 2025
CERTH
Machine Learning Engineer & IoT Developer
  • Developed a reinforcement learning optimisation system for multi-source heat pump control, dynamically selecting between ambient air, geothermal, and solar energy sources to maximise COP — part of the SEEDS project.
  • Designed edge computing solutions for IoT data execution and sharing in smart building energy management systems — part of the SEED4AI project.
Reinforcement LearningPyTorch TensorFlowIoT / Edge
Jul 2022
Sep 2022
CERTH
Machine Learning Engineer — Internship
  • Prototyped ML models for predictive maintenance of photovoltaic systems, focused on State of Charge degradation forecasting.
Pythonscikit-learn

Precipiteau Owner

Fully self-built operational platform delivering five precipitation data products across 35+ European countries: radar rain-rate, radar–satellite fusion, daily accumulation, raw reflectivity (ZhMax), and a 1-hour optical-flow nowcast. Custom Ramer ice-fraction algorithm on a 1 km terrain DEM for full precipitation-type diagnosis. GPU-accelerated rendering, 15-minute refresh cycle, 24/7.

PySTEPSFastAPILeafletOPERAICON-EUH-SAFxarraySciPyGeoPandasrasterio

ECMWF Bias Correction Pipeline

WeatherXM

Production XGBoost pipeline correcting systematic biases in ECMWF 51-member seasonal ensemble forecasts using ERA5 reanalysis across 14+ global regions — achieving +52% HSS improvement for precipitation and 30–50% RMSE reduction for temperature, with 25–29% RMSE reductions across wind speed, humidity, and pressure.

ECMWFXGBoostERA5xarrayscikit-learnDaskCDS APIpandas

Environmental Pollution Detection using Deep Learning

MSc Thesis · Aristotle University of Thessaloniki

End-to-end deep learning pipeline for detecting air pollutants from silicon photonic SHFT spectrometer data — combining a denoising autoencoder for sensor compensation with a 1D CNN classifier. Research resulted in a paper submitted to EANN 2026.

Deep LearningPyTorchAutoencoders1D CNNTransfer LearningEnvironmental AI

Parametric Insurance Automation

WeatherXM · ParahubXM

Automated parametric contract resolution for travel insurance and crop/farmer protection, processing ERA5 precipitation fields to classify risk via threshold-based event triggers — fully replacing manual adjudication.

ERA5Climate RiskxarraypandasnetCDF4Redis

Weather Data Downloader

WeatherXM

Python CLI and library for bulk-downloading ERA5 reanalysis from Google Cloud ARCO-ERA5 (Zarr) and ECMWF seasonal forecasts from Copernicus CDS. Supports batch multi-station downloads with 3×3 grid spatial extraction, automatic unit conversion, geocoding, and structured Parquet output to local or S3 storage.

ERA5CDS APIxarrayDaskZarrParquetAWS S3
Oct 2023 — Nov 2025
MSc in Artificial Intelligence GPA 9.26 / 10
Aristotle University of Thessaloniki
Thesis: Environmental Pollution Detection using Deep Learning
Coursework: Machine Learning · Deep Learning · Computational Intelligence · Biosignal Analysis · Intelligent Agent Systems
Oct 2017 — Dec 2022
MEng in Electrical & Computer Engineering GPA 7.19 / 10
Democritus University of Thrace
Thesis: Autonomous Driving and Obstacle Avoidance System of a Small Electric Vehicle
Coursework: Probability & Statistics · Signals & Systems · Algorithms & Data Structures · Control Systems · Renewable Energy · Sensors · Scientific Computing
Under Review — EANN 2026
Autoencoder-Based Compensation of Fabrication and Thermal Effects in SHFT Spectrometers for Gas Detection
S. Papargyris, L. Avramelou, M. Kirtas, C. Fu, S. Toxqui Rodríguez, C. Alonso Ramos, N. Passalis, N. Pleros, A. Tefas
19th Artificial Intelligence Applications and Innovations Conference (EANN 2026) · Notification April 2026
Published — Zenodo 2026
Floods in Southern Suburbs of Athens (January 2026)
S. Keppas, E. Dimitriou, A. Papadopoulos, S. Papargyris, N. Pagkratis
Zenodo Data Paper · February 2026
doi:10.5281/zenodo.18610297 →
Python SQL bash MATLAB HTML C C++
Certifications
Deep Learning Specialization DeepLearning.AI · Coursera
Machine Learning Specialization DeepLearning.AI · Coursera
Python 3 Programming Specialization University of Michigan · Coursera
Mathematics for Machine Learning Specialization Imperial College London · Coursera
SQL Course Udemy
English Proficiency (C2) University of Michigan
Languages
Greek — Native English — Proficient