Eric Chang avatar Eric Chang e0pwr

Freelance Developer / Web, Backend, Infra & Security

Eric Chang (e0pwr)

Turning web, infra, security, and documentation work into deployable MVPs.

Student in Information Management at National Dong Hwa University. Freelance focus: web apps, backend APIs, deployment, security testing support, and automation tools.

EmailGitHubPortfolio / BlogLinkedIn
  • Taiwan / Remote
  • National Dong Hwa University
  • Special Talent Admission, Academic Year 113
  • CTF player in ICEDTEA / B33U 50UP

01

About

Hi, I am Eric. I usually go by e0pwr online, but Eric is fine. I use my blog for notes, CTF writeups, and technical logs, even if I do not update it as often as I would like.

I learn best through building. I work with Linux, networking, HomeLab setups, full-stack development, cybersecurity, and CTF practice, and I am currently interested in tech devices and AI agent workflows.

I usually think through a project from requirements, database and API design, frontend and backend implementation, Docker / Nginx deployment, and documentation so the result is deployable, maintainable, and understandable for non-technical clients.

Security & CTFInfraHomeLabFull Stack DevelopmentAI Agentosu!

02

Work Experience

Infra Team

RiceCall · Self-employed / Infra Support

Nov. 2025 - Present

Remote

Supports hosting, networking, and infrastructure work for RiceCall, an unofficial RaidCall-compatible open-source project.

  • Helps organize host and network environments, including deployment, connectivity, and operations issues.
  • Supports infrastructure task breakdown and documentation so maintainers can track deployment state and maintenance workflows.
InfraNetworkingLinuxSelf-hosted GitHub Repo

Freelance Web Developer

Self-employed · Freelance

Jul. 2025 - Present

Taiwan / Remote

Builds web, backend, VPS deployment, automation, and technical documentation work for freelance clients.

  • Turns unclear requirements into deliverable features, including MVP scope, data structure, API design, and deployment planning.
  • Uses VPS, Python, automation scripts, Docker, Nginx, and frontend frameworks to ship small systems and tools.
VPSPythonWeb AppsDockerNginx

Information Technology

Taiwan Academic Network Roaming Center (TANRC) · Part-time

May 2025 - Present

Taiwan / Remote

Part-time role connected to an eduroam project and a SITCON 2025 Lightning Talk.

  • Manages eduroam roaming and RADIUS server proxy rule configuration and maintenance tasks.
  • Helps organize roaming service notes, network settings, and technical documentation for operations and handoff.
eduroamRADIUSNetworkDocumentation

03

Services

Web / Backend Landing pages, business websites, event websites, admin MVPs, REST APIs, forms / auth / CRUD systems, dashboards, custom web apps
DevOps / Infra Linux server setup, Docker / Docker Compose, Nginx reverse proxy, PostgreSQL / Redis, Cloudflare / domain / HTTPS setup, HomeLab documentation
Automation Tools Python / Shell scripts, batch data processing, simple scraping and data cleanup, CLI tools, FFmpeg automation, system maintenance helpers
Security Support Authorized web security checks, SQL injection / access control testing support, CTF challenge analysis, Linux / network / reverse engineering learning analysis, remediation notes

04

Technical Skills

Languages Python, TypeScript / JavaScript, HTML / CSS, Bash / Shell Script, SQL, basic PowerShell
Frontend Next.js, React, Tailwind CSS, Astro, Zustand, Recharts, basic UI / dashboard design
Backend / API Node.js / TypeScript backend, Hono, Flask, REST API design, Zod, Drizzle ORM
Database / Infra PostgreSQL, Redis, Linux, Docker / Docker Compose, Nginx / Reverse Proxy, Cloudflare, Git / GitHub, pnpm / Turborepo
Network / HomeLab Proxmox, VM / GPU passthrough, DNS, NAT, iptables, PPPoE, reverse proxy debugging
Security / CTF Web security fundamentals, basic SQL injection testing, reverse engineering fundamentals, GDB / IDA Free, introductory binary analysis, Linux permission and service analysis, CTF writeups
Workflow Tools Postman / curl, ffmpeg, tmux, Arch Linux / macOS / Windows, CLI-based workflow

05

Selected Projects & Practice

Taxi Dispatch System MVP

Demo

A taxi dispatch MVP built with a monorepo structure, including backend APIs, a passenger client, a driver client, and an admin dashboard.

Tech pnpm, Turborepo, Hono, Drizzle ORM, PostgreSQL, Zod, Next.js, React, Tailwind CSS, React Native, Expo, Redis, Docker Compose
Features Passenger ride request flow, driver order flow, admin order management, driver location updates, dashboard statistics, auth / OTP demo flow
Docs System architecture diagram, ER diagram, deployment diagram, state machine
Shows Full-stack system decomposition, API endpoint design, database schema design, monorepo planning, frontend-backend integration, technical writing

HomeLab / Reverse Proxy / Self-hosted Services

Article

Built and documented a HomeLab and internal services using FortiGate, Nginx Proxy Server, and multiple devices for routing and service deployment.

Tech FortiGate 50E, PPPoE, NAT / DMZ, Nginx Reverse Proxy, Docker Compose, NAS / self-hosted services, Cloudflare, HTTPS
Work Planned internal and external service routing, organized reverse proxy and domain settings, deployed self-hosted services, and documented maintenance workflows
Shows Linux server maintenance, reverse proxy routing, network architecture understanding, deployment debugging, documentation and architecture organization

Automation & Tooling

Uses Python, Shell Script, ffmpeg, Docker, and CLI tools to organize personal workflows.

Examples FFmpeg video processing parameter tuning, Python multithreaded scanner experiments, fast service deployment with Docker Compose, CLI workflow organization, tmux / cron automation experiments
Shows Practical scripting, workflow automation, CLI tool integration, debugging, and environment setup

06

Evidence

CTF

THJCC CTF 2026 Public 2026/03 #9
AIS3 EOF 2026 Finals w/ ciallo (∠·ω )⌒★ 2026/02 Finalist
AIS3 EOF 2026 Qual w/ ciallo (∠·ω )⌒★ 2025/12 Qualified
osu!gaming CTF 2025 w/ DACSSC 2025/10 #25
AIS3 Pre-exam 2025 2025/06 #103
THJCC CTF 2025 Public 2025/03 #35
AIS3 MyFirstCTF 2024 2024/04 #?

Speaker

SITCON Lightning Talk Mar. 2025 eduroam Security

Community

SITCON 2026 Attendee
DEVCORE CONFERENCE 2026 Attendee
SITCON 2025 Attendee & Lightning Talk speaker
DEVCORE CONFERENCE 2025 Attendee
DEVCORE CONFERENCE 2024 Attendee

Courses & Programs

AIS3 2025 Summer Program Participant
SecurityFocusOnline Participant

07

Freelance Collaboration

Good Fit

Small websites, school or club systems, admin MVPs, API integration, database-backed systems, Dockerized deployment, basic server / reverse proxy setup, technical documentation, and authorized web security checks.

Workflow

  1. Clarify requirements and project scope
  2. Split MVP features from future extensions
  3. Propose technical approach and timeline
  4. Build core functionality
  5. Test and revise
  6. Deploy and deliver documentation
  7. Provide maintenance or follow-up extensions when needed

08

Education

National Dong Hwa University

Department of Information Management

Admitted through the Special Talent Admission program, with a study focus on information security, software development, and system architecture.

Strengths

  • Understands web, infrastructure, and security workflows across frontend, backend, and deployment
  • Uses Linux, Docker, and CLI tools for practical technical work
  • Can turn technical problems into documentation, diagrams, and deliverables
  • Learns new tools and frameworks quickly through hands-on practice
  • Prefers using MVPs to validate requirements
  • Helps non-technical clients turn vague needs into concrete features