Engineering scalable AI systems, building and deploying deep learning models, fine-tuned LLMs, and AI agents on AWS, with a strong full-stack engineering background of 10+ years.
Selected Projects
A chemical AI agent that can predict molecular properties given a substance.
A machine learning model hosting platform, handling deployment, API management, and fine-tuning.
A Greek social platform for open discussion, community building, and content sharing through posts, comments, and voting.
A silly little game I developed with Phaser 3 during the Covid19 quarantine.
A Command Line Interface (CLI) consuming an actively written-to CLF HTTP access log written with Node.js
Work Experience

Machine Learning Engineer
National Technical University of Athens
Feb 2024 - Present

Senior Full-stack Engineer
Mercedes Benz via Mimacom
Feb 2023 - Feb 2024

Senior Full-stack Engineer
Gigabank
Jul 2022 - Feb 2023

Senior Full-stack Engineer
Impala Travel
Mar 2021 - Jun 2022

Senior Full-stack Engineer
Glovo
Feb 2020 - Feb 2021

Senior Full-stack Engineer
Alpha Innovation, Telefonica
Nov 2018 - Feb 2020

Full-stack Engineer
Marfeel
Apr 2016 - Nov 2018

Summer Student
CERN
Jun 2014 - Sep 2014

Full-stack Engineer
European Dynamics
Apr 2014 - Apr 2016

Full-stack Engineer
Sapila.gr (Personal Project)
2014 - 2020
Blog
The 5 worst bugs I've seen on production - #1 the N+1 problem
A tiny JOIN turned one request into ~100 queries—the graph looked like a heartbeat.
The 5 worst bugs I've seen on production - #2 the infinite crawler
A 'Back to start' button shared the Next selector, looping forever and flooding the DB.
The 5 worst bugs I've seen on production - #3 the €300,000 double refund
A refund path ran twice for 15 minutes, costing €300k before a sanity check caught it.
The 5 worst bugs I've seen on production - #4 the $60 otp ddos
An OTP endpoint was abused across many IPs; budget burned twice after no action items.
The 5 worst bugs I've seen on production - #5 the animation memory leak
Long sessions leaked ~2MB per animation; snapshots revealed unreleased lottie instances.
Microlearning is the new way to learn
How I use microlearning to keep up with fast-moving tech trends through short, daily doses of content across social media and YouTube.
Coding with Claude code and LLMs: What I've learned after 3 months
Reflections on working daily with Claude Code and LLMs for three months, the benefits of full repo context, and why experience still matters.
My experience with arrogant developers
A reflection on developer culture, code consistency, and the damage caused by ego-driven decisions in software teams.
The luxury of letting ideas marinate
This post explores the power of letting ideas sit. It reflects on how having time, space, and a clear mind can lead to better solutions , especially in engineering and research. It contrasts rushed patches with well-thought-out fixes that emerge when pressure is low and the mind is calm.
I asked AI about the future of AI (Yes, AI-ception)
I wanted to know: where is AI going in the next 10+ years? Is diving deeper into large language models (LLMs) in 2025 still a good bet for developers like me? What jobs will rise? What skills will matter?
Connect
Feel free to contact me at alex.arvanitidis0@gmail.com