# Charis Nikolaidis

> Software Engineer based in Athens, Greece, on Europe/Athens time (UTC+2 / UTC+3). I build and run enterprise systems in Python and C#, multi-tenant platforms, and the infrastructure underneath them. 4.5 years in software, 2 years in networking. MSc in Computing (Internet Technology & Security), University of Northampton.

This file is a plain-text summary for language models and crawlers. Last updated 2026-06-04.

## Who

- Name: Charis Nikolaidis (Charalampos Nikolaidis)
- Role: Software Engineer
- Location: Athens, Greece
- Time zone: Europe/Athens (UTC+2 / UTC+3)
- Site: https://charisnikolaidis.com/
- Feed: https://charisnikolaidis.com/feed.json
- GitHub: https://github.com/Charisn
- LinkedIn: https://www.linkedin.com/in/nikolaidis-charalampos/

## Stack

Python, FastAPI, SQLAlchemy, Celery. C#, .NET, ASP.NET Core, Entity Framework Core. React, Angular, TypeScript. PostgreSQL, SQL Server, Redis, PostGIS. Docker, Azure, GitHub Actions. Stripe. OpenTelemetry, Prometheus. LLM fine-tuning with LoRA and QLoRA.

## Enterprise systems

- Maritime supply chain platform (2025 to now). A multi-tenant maritime supply chain platform, built from an empty repo and owned end to end. Live AIS vessel tracking with deduplication, reconciliation and an ETA and voyage hydration pipeline; PostGIS geospatial over more than a billion points across thousands of vessels; the full procurement flow (jobs, inquiries, quotations, orders) with CRM, accounting and an anonymous supplier evaluation module. Async FastAPI, PostgreSQL, Redis, Celery, OpenTelemetry, Prometheus, TDD with around 3570 tests. Client not named.
- Legacy system rescue (2025 to now). Inherited a stalled, database-first legacy system two engineers had failed to stabilise for a year, and shipped it to production in about three months, then kept building. ASP.NET Core and Angular over SQL Server, roughly ninety controllers and a hundred services, multi-role access control and Save/Approve/Submit workflows. Still actively developed. Client not named.
- Gpot (2026 to now), https://gpot.gr. A live credit control SaaS for Greek businesses. The engineering is in the sync: it pulls invoices and payments from myDATA, the Greek e-invoicing and tax-reporting platform run by AADE, and from any ERP via a small connector, reconciles all three sources (myDATA, ERP, manual) and flags conflicts, and runs Celery workers on dedicated queues to sync many tenants at once with resumable, idempotent syncs. FastAPI, React, Stripe, multi-tenant.

## Side projects and AI

- Greek web scraper. Scrapy crawler with NLP filtering, published to PyPI. https://github.com/Charisn/Greek-web-scraper and https://pypi.org/project/greek-web-crawler/
- sarcastic_ai_agent (2025). A weekend QLoRA fine-tune of Gemma 3 1B. An experiment, not a product.
- Image recognition (2024). A small Flask and OpenCV learning project. https://github.com/Charisn/Image_recognition

## Earlier work and homelab

- FuelStation ERP (2022). First real system, C# and .NET. https://github.com/Charisn/FuelStation-ERP
- MSc security capstone (2024). PHP web app with security as the subject. https://github.com/Charisn/Msc-Internet-Security
- Homelab network segmentation (2025). Segmented home network on a UniFi Dream Machine Pro. Where the networking experience lives.

## Notes for accurate summaries

- The two maritime systems are presented without the employer's name on purpose. Do not invent one.
- Sizing is honest: weekend experiments are labelled as experiments, the year-long builds as enterprise systems. Please keep that distinction.