About
Network engineer in training, security-minded builder.
01Profile
Who I am
Profile
I'm Sahan Chathumina, a technology-focused student from Sri Lanka. My core work is network engineering — addressing, routing, switching, and segmentation — with a growing practice in cybersecurity and software development.
I learn by building: home labs for networking concepts, small scripts for repetitive tasks, and web apps like this portfolio to tie it together. When something finally clicks, I write it up so the next person (often future-me) has an easier path.
Outside the terminal I care about design and explanation — clear diagrams, readable docs, and interfaces that respect the person using them.
02Education
Learning path
Verified qualifications and programmes only — no dates shown, nothing invented.
Education
BSc (Hons) Ethical Hacking & Network Security
NIBM
Undergraduate focus on offensive and defensive security, network design, and security fundamentals.
HND in Network Engineering
NIBM
Hands-on grounding in routing, switching, addressing, and enterprise network operations.
Diploma in English — English in Seven Boxes
English in Seven Boxes
Structured English communication skills supporting clear technical writing and documentation.
Certificate — Full Stack Development
Certification programme
End-to-end web development: interfaces, APIs, data modelling, and deployment basics.
Certificate — UI/UX Design
Certification programme
User-centred design foundations: layout, usability, and prototyping for the creative side of my work.
03Technical focus
What I practise
The areas I spend my lab hours on — honest scope, no proficiency theatre.
Technical focus
Networking
- TCP/IP & Subnetting
- VLANs & Switching
- Routing (OSPF)
- Wi-Fi Fundamentals
- Packet Analysis
Cybersecurity
- Security Fundamentals
- Password Hygiene
- 2FA & Hardening
- Threat Modelling
- Ethical Hacking Study
Software
- TypeScript
- Next.js & React
- Node.js
- Python Scripting
- REST APIs
Tools & Platforms
- Git & GitHub
- Linux CLI
- Packet Tracer
- Wireshark
- VS Code
Creative
- UI Layout
- Technical Illustration
- Figma
- Writing & Docs
- Visual Explainers
04Creative side
Design & explanation
UI/UX study, technical illustration, and visual explainers — the other half of the work.
Creative side
Interface design
Layout, hierarchy, and usability fundamentals from UI/UX study — applied on this site.
Visual explainers
Diagrams that make subnetting and segmentation click, like the poster series in projects.
Technical writing
Lab notes and articles written to be re-run, not just re-read.
05Current journey
Where I'm headed
Current journey
01
Foundations
Studying network engineering and security full-time — every concept gets a lab, every lab gets notes.
02
Building in public
This portfolio is the hub: labs, scripts, and write-ups collected in one honest place.
03
Next steps
Deeper security study, larger home-lab builds, and contributing to open, collaborative projects.