I’m an offensive security engineer based in Brussels. I graduated cum laude from Howest and did my final internship at EUROCONTROL’s EATM-CERT, where I co-engineered an aviation CTF played by 113 security professionals.
Selim Celebi, offensive security engineer in Brussels. Open to offensive security roles, in Brussels or remote.
| Experience | EUROCONTROL, EATM-CERT, trainee, February to May 2025. Co-engineered the 2025 Aviation CTF: 113 experts, 34 organisations, 28 teams. Pentesting of aviation systems and applications. |
|---|---|
| Education | Howest, Applied Computer Science, Cyber Security Professional track. Graduated cum laude. |
| Results | TryHackMe Hackfinity Battle 2025, top 7%. HackTheBox Cyber Apocalypse 2025, top 8%. Cyber Security Challenge Belgium, four editions. |
| Work | Security audits of a company and a pharmacy, a honeypot lab, a deliberately vulnerable Android app, a network pentest report. |
| Skills | Web, network and system pentesting, OSINT, phishing simulation, malware analysis, reverse engineering, digital forensics. |
| Tools | Java, C, C++, C#, Kotlin, SQL, Bash. Linux, Windows Server, Git, CCNA-level networking. |
| Languages | French and Turkish native, English C1, Dutch B1. |
Background
I studied Applied Computer Science at Howest, on the Cyber Security Professional track, and graduated cum laude. The programme covered both sides of the field, building systems properly and then taking them apart, and I leaned firmly towards the second.
Outside the curriculum I compete in capture-the-flag events and follow the Belgian security scene: Cyber Security Challenge Belgium every year since 2023, talks from Belgian Cyber Command and the EU MITRE ATT&CK community, and the occasional hacking show. Notes from those are in the write-ups.
Experience
EUROCONTROL, EATM-CERT
EATM-CERT is the computer emergency response team for European air traffic management.
- Co-engineered the 2025 Aviation CTF, played by 113 experts from 34 organisations in 28 teams. Photos and details.
- Penetration testing of aviation systems and applications.
- Research supporting aviation cybersecurity.
Competitions
- TryHackMe Hackfinity Battle 2025: ranked #295 of 4,356 teams, top 7%.
- HackTheBox Cyber Apocalypse 2025: ranked #614 of 8,129 teams, top 8%.
- Cyber Security Challenge Belgium: four editions, 2023 to 2026.
- Hack the Future 2024, Antwerp: Mission Among the Stars.
Selected work
Full security audits of a company and a pharmacy, a honeypot lab run as red versus blue, a deliberately vulnerable Android app and a network pentest report. Each is described on the projects page.
Skills
Offensive: web application pentesting, network and system pentesting, phishing simulation, OSINT.
Analysis: malware analysis, reverse engineering, digital forensics.
Programming: Java, C, C++, C#, Kotlin, SQL, Bash.
Systems: Linux, Windows Server, Git, CCNA-level networking.
Languages
French and Turkish native, English C1, Dutch B1.