# Kostarkis

[@kostarkis](https://hacklab.so/kostarkis)

Kostarkis is Founder at Stealth Startup. No AI coding activity was synced in the last 30 days.

Building CogniCap and training data for humanoid robots\. Background in physical AI, embedded systems, physics, AI consulting and polar\-research IoT\.

Joined: 2026-08-07

1 followers · 0 following

## Links

- [GitHub](https://github.com/Kostarkis)
- [LinkedIn](https://linkedin.com/in/kostarczyk)

## AI usage (All time)

Total tokens: 571,056,700

| Harness | Tokens | Share | Most-used model |
| --- | ---: | ---: | --- |
| Claude Code | 569,895,376 | 99.8% | claude\-opus\-5\-5 |
| Codex | 1,161,324 | 0.2% | gpt\-6\-astra |

## Accomplishments

### [elektromagnetyzm](https://github.com/Kostarkis/elektromagnetyzm)

Public HTML repository of interactive animations of electromagnetism formulas and topics for the Fizyka II \(FUW\) physics course; the repository description is in Polish\. Owner of the repository, created June 2026\.

## Experience

### Founder — Stealth Startup

2026\-01 – Present

Warsaw, Poland

Founder role in a stealth startup\. The profile headline identifies the current focus as high\-precision, training\-ready egocentric data for humanoid robots; the company name is not supplied\.

### AI Consultant and Trainer — AI wizards

2023\-08 – 2025\-11

Warsaw, Poland

AI consulting and training role following an earlier prompt\-engineering and analysis position\.

### Co\-Founder — APPI Marketplace

2023\-02 – 2025\-01

Warsaw, Poland

Engineered and launched an AI\-powered platform with \.NET and Python\. Integrated LLMs for document querying and worked directly on prompt engineering, retrieval\-augmented generation, fine\-tuning and system architecture\.

### AI Prompt Engineer & Analyst — AI wizards

2023\-02 – 2023\-08

Warsaw, Poland

Prompt\-engineering and analysis role within AI wizards\.

### Co\-Founder — ExtremeBox

2019\-11 – 2023\-02

Designed and prototyped a durable IoT device for polar\-climate research, collaborating with scientists and a polar explorer\. Tested on Svalbard and Antarctica and optimised power management and data transmission for limited batteries in sub\-zero conditions\. The project received Young Innovator and EUCYS laureate recognition and was an Explory finalist\.

### Chief Technology Officer — 3CLASS

2020\-03 – 2021\-05

Gdynia, Poland

Developed the 3CLASS peer\-tutoring platform\. The profile reports first place in the education category among over 100 teams and more than 7,000 hours of volunteer tutoring facilitated during the pandemic\.

## Education

### Bachelor's studies, Physics — University of Warsaw

2025\-09 – Present

Physics programme listed September 2025–June 2028\. June 2028 is a future expected endpoint, not a completed degree\.

### Bachelor's studies, Artificial Intelligence & Management — Kozminski University

2023\-09 – 2026\-06

AI and management programme listed September 2023–June 2026, refining the earlier undated Hacklab study entry\.

### Engineering studies, Data Engineering and Analysis — Warsaw University of Technology

2022\-07 – 2023\-09

Study period in data engineering and analysis, listed July 2022–September 2023; no additional completion claim is inferred\.

### Secondary education, Mathematics, Physics and Computer Science — III Liceum Ogólnokształcące im\. Marynarki Wojennej RP w Gdyni

Graduate entry listed for 2019–2022, focused on mathematics, physics and computer science\. Months are not supplied\.