Kostas Psychogios - Data Science Contractor

Q: Where is Kostas based?

Kostas is based in Athens, Greece .

Q: What languages does Kostas speak?

Kostas speaks the following languages: Greek (Native), English (Advanced), German (Intermediate) .

Q: How many years of experience does Kostas have?

Kostas has at least 4 years of experience. During this time, Kostas has worked in at least 2 different roles and for 4 different companies . The average length of individual experience is 1 year and 1 month . Note that Kostas may not have shared all experience and actually has more experience.

Q: What is Kostas's latest experience?

Kostas's most recent position is Data Science Contractor at Elsevier .

Q: What companies has Kostas worked for in recent years?

In recent years, Kostas has worked for Elsevier , Synthetica , Synelixis Solutions , and Alexander Moore .

Q: Which industries is Kostas most experienced in?

Kostas is most experienced in industries like Information Technology , Retail , and Education .

Q: Which business areas is Kostas most experienced in?

Kostas is most experienced in business areas like Information Technology , Product Development , and Research and Development . Kostas also has some experience in Business Intelligence and Customer Service .

Q: What is Kostas's education?

Kostas holds a Master in Electrical and Computer Engineering from National Technical University of Athens (NTUA) .

Q: What is the availability of Kostas?

Kostas is immediately available full-time for suitable projects.

Recommended expert

Athens, Greece

Experience

Apr 2025 - Dec 2025

9 months

Amsterdam, Netherlands

Data Science Contractor

Elsevier

Created an evaluation pipeline for a RAG system using an LLM-as-a-judge approach, incorporating answer quality metrics such as comprehensiveness and harmfulness, as well as custom reproducibility and consistency metrics.
Implemented workflow enhancements in the existing RAG system, expanding business case coverage and increasing customer sales by 20%.
Improved the existing RAG model by adding error-handling branches to ensure a valid answer is always returned.
Collaborated with subject matter experts to design evaluation datasets for key components of the pipeline, including question rephrasing, document retrieval, and answer generation.

Jan 2024 - Apr 2025

1 year 4 months

Athens, Greece

Data Scientist

Synthetica

Developed a RAG-based agent system for complex files (PDF, Word, scanned images, often multilingual) that accurately retrieved and generated relevant information for users using OCR, segmentation, and vision LLM models to handle unstructured documents containing figures, tables, and scanned pages.
Fine tuned an embedding model with a custom dataset and labels, achieving higher accuracy compared to the baseline with Hugging Face on a multi-GPU setup.
Operated in an agile environment with bi-weekly sprints and regular daily/weekly meetings.
Utilized Docker to deploy models and APIs, and employed Kubernetes to manage Google Cloud resources.

May 2022 - Jan 2024

1 year 9 months

Athens, Greece

Data Scientist

Synelixis Solutions

Implemented an intrusion detection system trained within a federated learning framework, achieving an F1-score of 95% in malicious packet detection using TensorFlow and TensorFlow Federated.
Developed a local style transfer technique using Facebook’s Segment Anything Model, achieving visually captivating results.
Employed software engineering tools and frameworks such as Docker, FastAPI, Flask, and Git to ensure efficient project reuse and version control.

Aug 2021 - May 2022

10 months

Athens, Greece

Data Scientist

Alexander Moore

Collaborated with two engineers to implement a sales forecasting system that accurately predicted weekly sales quantities for over 100 products using statsmodels, scikit-learn, and Keras.
Developed an NLP-based sentiment analysis module utilizing TensorFlow and NLTK, achieving a 90% accuracy rate in classifying customer comments in real-world scenarios.
Built and deployed a churn prediction model that reduced client operational costs by 20% through accurate user classification.

Industry Experience

See where this freelancer has spent most of their professional time.

Experienced in Information Technology, Retail, and Education.

Information Technology

Retail

Education

Business Area Experience

See which departments and functions this freelancer has contributed to most.

Experienced in Information Technology, Product Development, Research and Development, Business Intelligence, and Customer Service.

Information Technology

Product Development

Research and Development

Business Intelligence

Customer Service

Skills

Python
Mysql
Pyspark
Sparksql
Bash Script
Pytorch
Tensorflow
Scikit-learn
Hugginface
Automl
Langchain
Llamaindex
Langgraph
Elasticsearch
Transformers (Gpt, Llama, Mistral, Bert, Vit, Vlbert, Vertex-ai Etc.)
Convolutional Neural Networks (Cnns)
Linux
Git
Docker
Kubernetes
Kubeflow
Flask
Fastapi
Django
Microsoft Azure
Azure Databricks
Google Cloud
Aws

Languages

Greek

Native

English

Advanced

German

Intermediate

Education

Oct 2015 - Jun 2021

National Technical University of Athens (NTUA)

Master of Engineering, Electrical and Computer Engineering · Electrical and Computer Engineering · Athens, Greece

Statistics

Experience

Total positions 4

Experience in Information Technology 3 y

Avg length 1 y 1 m

Longest experience 1 y 8 m

Global Experience

Countries worked in 2 (Greece, Netherlands)

Primary country Greece

Expertise

Recent roles Data Science Contractor, Data Scientist

Main industries Information Technology, Retail, Education

Main business areas Information Technology, Product Development, Research and Development

Qualifications

Highest degree Master

Profile

Created

December 2025

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Frequently asked questions

Do you have questions? Here you can find further information.

Where is Kostas based?

Kostas is based in Athens, Greece.

What languages does Kostas speak?

Kostas speaks the following languages: Greek (Native), English (Advanced), German (Intermediate).

How many years of experience does Kostas have?

Kostas has at least 4 years of experience. During this time, Kostas has worked in at least 2 different roles and for 4 different companies. The average length of individual experience is 1 year and 1 month. Note that Kostas may not have shared all experience and actually has more experience.

What roles would Kostas be best suited for?

Based on recent experience, Kostas would be well-suited for roles such as: Data Science Contractor, Data Scientist.

What is Kostas's latest experience?

Kostas's most recent position is Data Science Contractor at Elsevier.

What companies has Kostas worked for in recent years?

In recent years, Kostas has worked for Elsevier, Synthetica, Synelixis Solutions, and Alexander Moore.

Which industries is Kostas most experienced in?

Kostas is most experienced in industries like Information Technology, Retail, and Education.

Which business areas is Kostas most experienced in?

Kostas is most experienced in business areas like Information Technology, Product Development, and Research and Development. Kostas also has some experience in Business Intelligence and Customer Service.

What is Kostas's education?

Kostas holds a Master in Electrical and Computer Engineering from National Technical University of Athens (NTUA).

What is the availability of Kostas?

Kostas is immediately available full-time for suitable projects.

What is the rate of Kostas?

Kostas's rate depends on the specific project requirements. Please use the Meet button on the profile to schedule a meeting and discuss the details.