Ioannis.dev

About Me

Hi, I'm Ioannis Maragkakis — a full-stack developer based in Thessaloniki, Greece, with over 3 years of experience building web applications and data-driven systems.

My background is in geophysics and data science. I worked with satellite imagery, seismic data, and large-scale ETL pipelines, and along the way I realized what I enjoyed most was building the tools themselves — the interfaces, the APIs, the systems that turn raw data into something people can actually use. That pulled me into full-stack development, where I now work across the stack with React, Node.js, TypeScript, and Python.

I care about clean, type-safe code, thoughtful UX, and shipping things that work reliably in production. Outside of work, I'm usually building side projects — lately around interactive maps and educational web tools.

Experience

Software Developer / Data Scientist

Jun 2025 — Present

VODA.ai — Boston, United States (Remote)

  • Built a data retrieval system integrating with NASA's CMR API to query and ingest satellite datasets.
  • Set up CI/CD pipelines using GitHub Actions with automated linting (Ruff) and test execution.
  • Implemented unit and integration tests across application and data pipelines, reducing deployment risk and improving production reliability.

Backend Developer / Python Developer

Oct 2024 — Mar 2025

emendSys — Thessaloniki, Greece

  • Designed and implemented RESTful APIs using FastAPI with asynchronous request handling.
  • Developed and deployed event-driven serverless services on Azure Functions for asynchronous data processing.
  • Architected type-safe backend pipelines using dataclasses, enums, and Pydantic to enforce strict data validation.
  • Implemented centralized logging and error handling to improve debugging and system reliability.

Data Scientist

Jul 2022 — Jul 2024

Accenture — Thessaloniki, Greece

  • Designed and implemented ETL pipelines for large-scale data processing workflows.
  • Optimized SQL-based data transformations and automated recurring workflows to reduce manual overhead.
  • Built analytical tools leveraging satellite datasets for environmental monitoring.
  • Developed an internal web platform using React and Tailwind CSS for visualizing GeoTIFF and GeoJSON data on interactive Leaflet maps.

Applied Geophysicist / Data Scientist

Apr 2021 — Jun 2022

Institute of Engineering Seismology & Earthquake Engineering — Thessaloniki, Greece

  • Built Python scripts for parsing and processing seismic record files.
  • Designed and developed a GUI application for interactive body wave arrival selection.
  • Aggregated and structured multi-source station data to generate a comprehensive earthquake catalogue.

Education

MSc — Environmental and Applied Geology

Aristotle University of Thessaloniki

2019 — 2022

BSc / MSc — Mineral Resources Engineering

Technical University of Crete

2013 — 2018

Skills

Frontend

React TypeScript Tailwind CSS Material UI Leaflet

Backend

Node.js Express FastAPI JWT

Databases

MongoDB (Mongoose) SQL

Tools & DevOps

Docker GitHub Actions (CI/CD) Azure Functions

Other

Python JavaScript Bash Git/GitHub

Languages

English French Spanish Greek (native)

Certifications

Full Stack Open (6 ECTS) — University of Helsinki

Grade: 5/5
  • Built full-stack applications using React, Redux, Node.js, and MongoDB.
  • Developed REST APIs with Express and implemented authentication.
  • Applied testing practices (Jest, Cypress) and CI/CD pipelines.
  • Designed and deployed production-ready web applications.

Achievements

Award of Academic Excellence

Limmat Stiftung