Hi, I'm Leonidas Papanastasiou

Experienced software engineer with 5+ years building scalable cloud-native systems, blockchain networks, and data-driven applications across finance, energy, and supply chain sectors.

5+ Years Experience
15+ Enterprise Clients
3 Award-Winning Projects

About

Software Engineer with 5+ years of experience building scalable cloud-native systems, blockchain networks, and data-driven trading tools. Expert in Django/FastAPI/React and Python-based architectures across finance, energy, and supply chain sectors.

Specialized in quantitative system optimization, algorithmic workflows, and data pipeline design for real-time analytics. Currently working as a Consultant - Quantitative Software Engineer at a Quantitative Hedge Fund in New York, designing scalable internal software solutions and enhancing Order Management Systems for high-frequency trading pipelines.

Cloud-Native Systems

Scalable architectures serving 5,000+ users

Blockchain Networks

Supply chain transparency solutions

Quantitative Trading

High-frequency trading systems

Data Engineering

Real-time analytics pipelines

Education

MSc in Data Science & Information Technologies
National & Kapodistrian University of Athens
Big Data & Artificial Intelligence
BSc in Informatics and Telecommunications
National & Kapodistrian University of Athens
Software Engineering & Algorithms
Top 3 Freshman 2:1 Honors

Experience

Quantitative Hedge Fund

Consultant - Quantitative Software Engineer
Sep 2025 - Present New York, US
Current Position

Designing scalable internal software solutions for high-frequency trading pipelines and enhancing Order Management Systems for real-time trade execution in quantitative trading environments.

Designed scalable internal software solutions aligning quantitative strategies with technical infrastructure
Enhanced Order Management System (OMS), improving execution latency and reliability
Resolved system bottlenecks, boosting application availability in high-volume trading environments

Wings ICT Solutions

Blockchain & Data Engineer
Apr 2023 - May 2025 Athens, Greece

Architected scalable private blockchain networks using Hyperledger Besu and implemented Flask-based RESTful microservices with 20+ endpoints for blockchain interaction layers.

Architected scalable private blockchain networks using Hyperledger Besu and custom Solidity smart contracts
Implemented Flask-based RESTful microservices with 20+ endpoints for blockchain interaction layers
Orchestrated serverless data ingestion, reducing latency by 50% and infrastructure costs by 25%

Evolution Projects+

Full Stack Engineer / Product Manager
Sep 2020 - Apr 2023 Athens, Greece

Led award-winning enterprise platform development scaling to 5,000+ users and delivered Django-based ML systems with 92% forecasting accuracy adopted by 45+ municipalities.

Delivered Django-based Waste Data Management System with 92% ML forecasting accuracy, adopted by 45+ municipalities
Led award-winning enterprise platform development: ReactJS/FastAPI/PostgreSQL system scaling to 5,000+ users
Built energy complaint portals and real-time geospatial systems handling 2,000+ field tickets

Liquimar Tanker Management Inc.

IT & Network Analyst
Jun 2018 - Apr 2020 Athens, Greece

Maintained enterprise IT systems and implemented secure network infrastructure with 99.9% uptime during COVID-19 remote work transition.

Maintained enterprise IT systems and implemented firewall/VPN policies for secure network infrastructure
Conducted stress tests simulating 100+ concurrent VPN sessions, ensuring 99.9% uptime during COVID-19 remote shift

Vision TV Entertainment

Cofounder & Lead Engineer
Jun 2016 - Apr 2017 Athens, Greece

Conceptualized and created innovative OTT content delivery platform using Python, Linux, and Raspberry Pi, integrated into one of Greece's largest telecom networks.

Conceptualized and created innovative OTT content delivery platform using Python, Linux, and Raspberry Pi
Integrated platform into one of Greece's largest telecom networks

Certifications & Awards

Professional Certifications

Finance
Machine Learning for Trading Specialization
Coursera / Google Cloud
2025

Advanced machine learning techniques applied to quantitative trading and financial markets.

Verify Certificate
Finance
Quantitative Finance & Algorithmic Trading
Udemy
2025

Comprehensive course covering quantitative finance, algorithmic trading strategies, and Python implementation.

Verify Certificate
Engineering
AI Engineering Professional Certificate
Coursera / IBM
2024

Professional certification in AI engineering, machine learning, and artificial intelligence systems.

Verify Certificate
Engineering
Ultimate Rust Crash Course
Udemy
2024

Comprehensive Rust programming course covering systems programming and performance optimization.

Verify Certificate

Awards & Recognition

1st Place
Best Information System & IoT Application
Industry Award
2022

Dynamic Workflow Management System (DEDA S.A.) - Award-winning enterprise platform.

Top 3
Athens Startup Weekend
Vision TV Entertainment
2017

Innovative OTT content delivery platform for the Greek market.

3rd Place
Mathematics Contest "Thalis"
Hellenic Society of Mathematics
2008

National mathematics competition showcasing analytical and problem-solving skills.

Speaker
18th InfoCom World Conference
Technology Conference
2016

Presented Vision TV Entertainment startup at major technology conference.

Skills

Programming Languages

Python JavaScript TypeScript C++ Go Rust SQL

Quantitative Finance & Trading

Algorithmic Trading Order Management Systems High-Frequency Trading Quantitative Analysis Risk Management Financial Modeling Market Data Processing

Backend & APIs

Django FastAPI Flask Node.js REST APIs GraphQL Microservices

Data & ML

Pandas NumPy Scikit-learn TensorFlow PyTorch Apache Airflow Jupyter

Cloud & DevOps

AWS Azure Docker Kubernetes Google Cloud Git CI/CD

Databases

PostgreSQL MongoDB MySQL Redis Supabase InfluxDB Elasticsearch

Frontend Development

React Next.js HTML5 CSS3 Flutter Material-UI Responsive Design

Blockchain & Web3

Solidity Ethereum Polygon Hardhat Foundry Solana Web3.js