Aaron Sawit
Security engineer · Singapore
Security engineer in Singapore with a first class computer science degree and the GCIH. My day job is security risk and compliance. My training is incident handling and hands-on attack and defence. In my own time I build and run real systems, including a suite of free learning tools used by students and teachers, and I have tutored special needs students for six years, so I am used to explaining hard things simply.
Experience
Cybersecurity Engineer, GovTech Singapore
Jul 2025 to present
Cybersecurity Specialist, Red Alpha Cybersecurity
Jun 2024 to Jul 2025
- Full-time blue team and red team training programme. Earned the GIAC Certified Incident Handler (GCIH) through SANS SEC504.
- Completed the Hack The Box SOC Analyst path and reached Level 5 of the CSIT TISC capture-the-flag.
Private Tutor, self-employed
May 2020 to present
- One-to-one tutoring for primary and lower-secondary special needs students, referred by a specialist from the Dyslexia Association of Singapore.
- The reason the Versed tools exist: I build what my own students need and keep it free.
Academic Coach, RoboThink
Jan 2022 to Jan 2023
- Taught robotics and beginner coding to children, adapting each lesson to the child's pace and reporting progress to parents.
Head Finance Clerk, Singapore Armed Forces
Feb 2018 to Feb 2020
- Handled about $250K in transactions a year to audit standard, and managed procurement with external vendors.
Skills
- Detection and response
- Log analysis, SIEM (Elastic Stack), Sysmon and Windows event logs, Sigma rules mapped to MITRE ATT&CK, incident handling (SANS SEC504), Snort, phishing analysis
- Security tools
- Nmap, Wireshark, tcpdump, Scapy, Netcat, Metasploit, Hashcat, John the Ripper, Mimikatz, CrackMapExec, enum4linux, Ligolo-ng, YARA, Splunk, Elastic, Sysmon, Snort, PowerShell
- Infrastructure and network
- Linux, Docker and Compose, systemd, iptables and policy routing, WireGuard and Tailscale, DNS filtering, backups and monitoring, infrastructure as scripts
- Cloud and application
- Cloudflare Workers, Durable Objects, D1 and KV, Pages Functions, TypeScript, authentication with scrypt and cookie sessions, rate limiting and abuse controls, CSP and security headers
- Programming
- Python (tested CLI tools, log pipelines), TypeScript and JavaScript, shell
- Frameworks
- MITRE ATT&CK, NIST CSF, ISO 27001
Selected work
Versed
Product suite, solo · 2026, ongoing
- Four free learning tools for students, tutors and teachers, designed, built and run by one person on Cloudflare's edge. No sign-up to play, no tracking, no budget.
- 4 products live · 0 accounts needed to play · 1 person: design, code, ops
One box, forty services
Infrastructure, self-hosted · 2026, ongoing
- A recycled gaming PC running forty-odd containers for my family: photos, passwords, media, DNS filtering, game streaming and local AI. Reachable from anywhere, with no port open to the internet.
- 40+ services · 0 ports open to the internet · 14 days of restorable backups
Local AI on 2017 hardware
Performance engineering · 2026
- Getting a 35-billion-parameter model to 66 tokens a second on two GTX 1080 Tis by measuring every assumption, including the ones in the documentation.
- 46 to 71 tokens a second · +44% on the same hardware · 1 crash found before it shipped
Detection tooling
Blue team, Python · 2024 to 2025
- Small, tested tools from my defensive security practice: a log triage pipeline that pairs rule-based detection with an LLM classifier, a phishing link analyser, and hand-written Snort and iptables rules.
- 4 Sigma rules, ATT&CK mapped, green in CI · 36 offline tests on the triage tool · 3 public repositories with passing builds
Education
BSc (Hons) Computer Science, First Class Honours
Coventry University, United Kingdom · 2023
Diploma in Information Technology
PSB Academy, Singapore · 2021
Training and certification
GIAC Certified Incident Handler (GCIH)
SANS SEC504: Hacker Tools, Techniques and Incident Handling
Hack The Box Academy
SOC Analyst path: SIEM, Windows event logs, incident handling
Red Alpha
Cybersecurity specialist training, Singapore
CSIT TISC CTF
Reached Level 5
Writing
- Cloudflare KV cannot enforce a rate limit, and how I found out
- My phone stopped using my DNS filter. It was iCloud Private Relay
- Jellyfin, ffmpeg 7.1 and the HLS segment with no extension
- Docker containers silently lose the GPU after a systemd reload
- Why xemu says "Please insert an Xbox disc" to a perfectly good image