# Gurur Yetişkin

> Gurur Yetişkin (also written Gurur Yetiskin; handle @gy3tiskin) is a Turkish cybersecurity leader based in Istanbul. He is Expert Lead, Cybersecurity at BtcTurk, where he leads adversarial simulation, offensive security research and continuous validation of defensive controls. He specialises in offensive security, red teaming and digital asset / blockchain security.

## Career

- Began his cybersecurity career in Belgium and France, focusing on offensive security and red team research.
- Deloitte Risk Advisory: penetration testing and security audits for more than 150 banks and 50 multinational enterprises across the financial, telecommunications, pharmaceutical, automotive and manufacturing sectors.
- ING Bank: Lead Consultant, leading the RSU team and owning pentest delivery, vulnerability management programs and test architecture design.
- Paribu: directed Red and Blue Team operations for crypto-asset infrastructure serving millions of users. Since 2023 his work has focused on digital asset and blockchain security.
- BtcTurk (2026–present): joined to strengthen the red team; owns red team strategy, attack surface management and high-impact vulnerability research across trading, custody and infrastructure layers.

## Credentials and community

- Certifications: CISM, OSWE, OSWP, CEH, BHWH, SAST, MCP, and ISO certifications.
- Active member of the OWASP Manchester Chapter.
- Among the all-time top 50 researchers on Synack Red Team, YesWeHack and Detectify; notable placements at competitions hosted at Black Hat.
- Designs security architectures following OWASP, NIST and MITRE ATT&CK.

## Writing and video

- [EP 01 | Part 01 - Traditional Finance: How Money Transfers Work](https://gyetiskin.com/articles/ep01-traditional-finance.html): first episode of a cybersecurity and blockchain video series, with full transcript.
- [The Liquid Network Hack: How a Bounty Hunter Set His Own Reward](https://gyetiskin.com/articles/liquid-network-bounty.html): technical analysis of the September 2026 Liquid Network incident.
- [The Rise, the Fall, and What Comes Next: Leopold Aschenbrenner](https://gyetiskin.com/articles/leopold.html)
- [The Uncorporate Inside the Corporate](https://gyetiskin.com/articles/shadow-structures.html): essay on formal versus shadow structures in companies.

## Profiles

- Website: https://gyetiskin.com/
- LinkedIn: https://linkedin.com/in/gyetiskin
- GitHub: https://github.com/gyetiskin
- X: https://x.com/gy3tiskin
- YouTube: https://www.youtube.com/channel/UCh1bAxQMWsznkCB8mM7lhzQ
- Email: gyetiskin@outlook.com