Home
# Barry O'Callaghan
**Cybersecurity tools, research, and writeups.**
[Blog :material-newspaper:](blog/){ .md-button .md-button--primary } [Projects :material-code-braces:](projects/){ .md-button } [About :material-account:](about/){ .md-button }
---
[Blog :material-newspaper:](blog/){ .md-button .md-button--primary } [Projects :material-code-braces:](projects/){ .md-button } [About :material-account:](about/){ .md-button }
---
I'm a cybersecurity professional based in Japan. I build open-source security tools, break things for a living, and write about what I learn. This site is where I share tools, writeups, and analysis — no hype, no vendor fluff.
Latest posts
Visit the Blog → for the full archive.
What I'm working on
- sec-headers — audit HTTP security headers in one command
- Weekly tool releases and deep-dive writeups
- Detection engineering and automation projects
:fontawesome-brands-github: GitHub :fontawesome-brands-linkedin: LinkedIn :material-email: Email