🛠️ Tech Knowledge Base & System Architecture
This engineering knowledge hub consolidates hands-on technical records and expertise gained as a systems engineer—spanning Cloud (AWS) Infrastructure Architecture, Production Incident Troubleshooting, Security Incident Response, and a Fully Automated Zero-Cost Serverless Pipeline.
Beyond high-level tutorials, this space documents deep-dive engineering practices: tracing system calls with strace, designing zero-downtime database migrations, and building permanently free (Always Free) serverless pipelines.
🧭 Technical Categories (Category Map)
Click on any article title in the tables below to read the detailed technical documentation.
1. ☁️ Cloud Infrastructure & Migration
Architecture design and migration practices focused on minimizing downtime and maximizing system reliability across cloud and on-premises environments.
| Article Title | Key Focus | Date |
|---|---|---|
| EBS Snapshot vs AMI: Technical Comparison for AWS Backup Strategy | AWS EBS/AMI snapshot mechanisms, Data Lifecycle Manager (DLM) RPO/RTO optimization | 2026-08-05 |
| Minimizing Downtime with RDS Blue/Green Deployment | Aurora MySQL major/minor version upgrades, replication lag management, sub-minute switchovers | 2026-07-28 |
| Importance of ARNs When Restoring Accidentally Deleted AWS SNS Topics | Restoring deleted SNS topics with identical ARNs to seamlessly reconnect CloudWatch Alarms | 2026-07-08 |
| Step-by-Step Legacy Server Migration Process | Phased transition of legacy PHP/MySQL stacks to modern OS and MariaDB with data integrity validation | 2026-05-17 |
| Server Disk Replacement: Why It's More Than a Simple Task | Filesystem unmounting, rsync incremental sync, fstab UUID verification, and live maintenance | 2026-05-17 |
2. 🛡️ Production Troubleshooting & Security
Rigorous troubleshooting case studies resolving silent daemon crashes, hardware communication failures, and real-world web server exploitation via log, packet, and system call analysis.
| Article Title | Key Focus | Date |
|---|---|---|
| Troubleshooting: React2Shell (CVE-2025-55182) Incident Analysis & Response | Remote Code Execution (RCE) root cause analysis, webshell quarantine, and emergency firewall response | 2026-05-17 |
| Troubleshooting Logless Apache SSL Crashes with strace | Diagnosing silent Apache startup crashes using strace to identify certificate permission and entropy issues | 2026-05-21 |
| Fixing MSSQL Configuration Manager Errors via Shared Feature Repair | Resolving WMI provider errors in SQL Server Configuration Manager by recompiling MOF files | 2026-07-20 |
| Why MRTG Traffic Graphs Fail to Explain Server Latency | Limitations of averaged bandwidth metrics; diagnosing packet loss, jitter, and TCP window constraints | 2026-07-10 |
| Network Security Configuration with FortiGate Firewall | DMZ network segmentation, Virtual IP (VIP) forwarding, and zone-based security policy design | 2026-05-17 |
| Lenovo Server XCC Unreachable Troubleshooting After IDC Relocation | Diagnosing physical IDC relocation issues, BMC/XCC port communication failures, and BIOS reconfigurations | 2026-06-26 |
3. ⚙️ Serverless Automation & Blog Architecture
The fully automated, zero-cost serverless architecture and multilingual static pipeline powering this platform.
| Article Title | Key Focus | Date |
|---|---|---|
| Enhancing VitePress Blog: Notion-Style Tags and Project Showcase | Notion-style tag badges, build-time data loaders, 4-project showcase, and CI/CD alerts | 2026-08-23 |
| Migrating Telegram Bot to AWS Lambda $0 Serverless: Troubleshooting Review | Achieving $0 VM cost, Lambda Function URL + DynamoDB session handling, and real troubleshooting | 2026-08-23 |
| Building a Multilingual Blog with VitePress | Setting up trilingual (KO/EN/JA) routing, custom dark theme, and components with VitePress | 2026-05-16 |
4. 🌐 Web Performance, Accessibility & Supply Chain Security
Optimizing SEO, Web Accessibility (A11y), eliminating render-blocking resources for perfect Google Lighthouse scores, and securing npm dependencies.
| Article Title | Key Focus | Date |
|---|---|---|
| Mobile Performance and Accessibility Optimization via Search Console | Data-driven optimization via Search Console: async CSS, GA4 deferred loading, 100 Lighthouse score | 2026-08-15 |
| VitePress Static Blog npm Dependency Vulnerability Analysis & Fix | Supply chain vulnerability mitigation with npm audit, CI/CD build hardening, and package overrides | 2026-08-09 |
🏗️ Modern System Architecture (AWS $0 Serverless Pipeline)
This platform (uoosnn.com) operates on an event-driven serverless architecture pairing AWS Always Free Tier with GitHub Pages, achieving $0 monthly operating costs and Zero-Ops infrastructure maintenance.
mermaid
flowchart TD
subgraph Client_Layer [User & Telegram Client]
User[Admin / User] -->|Messages / Photos / /post commands| TG[Telegram Bot API]
end
subgraph AWS_Serverless [AWS Always Free Serverless Layer ($0 Cost)]
TG -->|HTTPS POST Webhook| FURL[Lambda Function URL\n(No API Gateway needed, $0)]
FURL --> LAMBDA[AWS Lambda\n(Python 3.12 / x86_64, 256MB)]
CRON[Amazon EventBridge\n(Daily 09:00 KST News Trigger)] -->|Scheduled Trigger| LAMBDA
LAMBDA <--> DYNAMO[(Amazon DynamoDB\ntelegram_bot_state / 25GB Always Free)]
end
subgraph AI_External [AI & External Services]
LAMBDA -->|Chat / Blog Generation / Multilingual Translation| GEMINI[Google Gemini API\n(Flash 2.5 / 3.0)]
LAMBDA -->|PyGithub REST API Direct Commits| GH_API[GitHub REST API\nuoosnn/uoosnn.github.io]
end
subgraph CI_CD_Hosting [Deployment & Global Hosting]
GH_API -->|main branch push event| ACTIONS[GitHub Actions\n(npm ci -> vitepress build)]
ACTIONS -->|sitemap.xml + feed.xml auto-generation| PAGES[GitHub Pages\n(Global CDN Static Hosting)]
end
PAGES -->|Fast Loading / Lighthouse 100| READER[Visitors (Web Browser)]💡 5 Core Principles of the Zero-Cost (Always Free) Architecture
- AWS Lambda (1M free requests/month):
- Eliminates 24/7 VM hosting costs by spinning up in under 100ms only when an event occurs. Personal bot usage consumes less than 0.01% of the monthly free allowance.
- Lambda Function URL ($0 HTTPS Endpoint):
- Connects Telegram Webhooks directly to Lambda without API Gateway overhead, keeping endpoint costs strictly at $0.
- Amazon DynamoDB (25GB Always Free Tier):
- Stores session state, conversation history, news deduplication records, and API usage counters in a single table (
telegram_bot_state) with a 7-day TTL for automated data cleanup.
- Stores session state, conversation history, news deduplication records, and API usage counters in a single table (
- PyGithub REST API Commits (Diskless I/O):
- Direct remote commits via GitHub REST API without requiring local Git binaries, storage volumes, or local repository cloning.
- VitePress + GitHub Pages (High-Speed Static Hosting):
- Compiles pure HTML/CSS/JS deployed to global CDNs, eliminating server-side attack vectors while maximizing page load performance.
📊 Tech Stack Overview
| Domain | Technology | Version/Tier | Role & Features |
|---|---|---|---|
| Frontend (SSG) | VitePress | v1.6.4 | High-performance SSG powered by Vue 3.4 |
| Design System | Custom CSS | 6:3:1 Palette | Dark/Light mode switch, Glassmorphism, responsive UI |
| Serverless Backend | AWS Lambda | Python 3.12 | Webhook receiver, async event dispatch, AI post generator |
| State Storage | Amazon DynamoDB | On-Demand | 25GB Always Free, session persistence, news history, TTL |
| Scheduler | Amazon EventBridge | Cron (09:00 KST) | Daily morning IT/Security news ingestion trigger |
| AI Models | Google Gemini API | Flash Models | Conversational post generation, real-time trilingual translation |
| CI/CD & Hosting | GitHub Actions / Pages | Ubuntu Latest | Automated build, multilingual RSS (feed.xml) and sitemap.xml |
| Comments | Giscus | GitHub Discussions | Serverless discussion system authenticated via GitHub OAuth |
| Analytics | Google Analytics 4 | gtag.js (Deferred) | 0ms TBT impact with deferred asynchronous tracking |
🌍 Multilingual Pipeline (Multilingual Engine)
Leveraging VitePress's native locales and Gemini AI translation, newly published Korean content is automatically translated and deployed across three languages simultaneously.
[Korean Original Post] ---> /blog/ or /tech/
│
├─── [Gemini AI Translation] ───> /en/blog/ or /en/tech/ (🇺🇸 English)
└─── [Gemini AI Translation] ───> /ja/blog/ or /ja/tech/ (🇯🇵 日本語)- Clean URL Structure:
ko(root),en(/en/),ja(/ja/) - SEO Optimization: Automatic injection of
hreflangtags,canonicalURLs, andTechArticle/BlogPostingSchema.org JSON-LD structured data.
🚀 Upcoming Engineering Topics
- 📌 Container Orchestration & Monitoring with AWS ECS / EKS
- 📌 Infrastructure as Code (IaC) with Terraform & AWS CDK
- 📌 Linux Kernel Tuning & Socket-Level Network Optimization
- 📌 Enterprise Observability with Prometheus and Grafana
Hand-crafted technical notes and troubleshooting records are continuously updated. Feel free to leave comments or connect via GitHub.