How-To Guides
Step-by-step scenario guides for solving various real-world problems. Each guide covers problem definition, required tools, core code, and common mistakes.
Computer Vision / Image Processing
Web Development
JWT Token Authentication
Build an Access/Refresh Token-based authentication flow for SPAs
CSS Responsive Layout
Build mobile-to-desktop responsive layouts with Flexbox/Grid
React State Management
Compare useState/useReducer/Context and choose the optimal pattern
API Rate Limiting
Implement API rate limiting with Token Bucket algorithm and Redis
TypeScript Generic Patterns
Generic utility types, conditional types, and type guard patterns
GraphQL API Design
Design GraphQL APIs with Apollo Server, solve N+1, implement auth
WebSocket Real-Time Communication
Build real-time chat, notifications, and live dashboards with Socket.IO
DevOps / Infrastructure
Docker Log Analysis
How to quickly trace error causes from container logs
K8s Pod Troubleshooting
Debug pod failures like CrashLoopBackOff using kubectl
Nginx SSL Reverse Proxy
Set up an HTTPS reverse proxy with Let's Encrypt + Nginx
GitHub Actions CI/CD
Build test, Docker build, and deployment pipelines with GitHub Actions
SSL Certificate Setup
Issue Let's Encrypt wildcard SSL certificates with auto-renewal
Linux Performance Tuning
CPU/memory/disk/network bottleneck analysis and sysctl kernel tuning
Terraform Infrastructure Management
Codify and automate AWS cloud infrastructure with Terraform IaC
Prometheus + Grafana Monitoring
Build Prometheus metric collection and Grafana dashboards
Security
Networking
Embedded Systems
Data / Automation
Excel to JSON API Integration
Clean Excel data with pandas and send it via REST API
Python Web Crawling
Automatically collect web data using requests + BeautifulSoup
Regex Data Extraction
Batch extract emails, phone numbers, and URLs using regular expressions
Python Data Analysis
Build data cleaning, aggregation, and visualization pipelines with Pandas/NumPy
Statistics
Database
SQL Query Optimization
Analyze slow query causes with EXPLAIN ANALYZE and tune indexes
MongoDB Aggregation Pipeline
Complex data analysis and transformation with MongoDB aggregation
Elasticsearch Search Engine
Build full-text search with Elasticsearch, text analysis, and autocomplete
Redis Caching Strategy
Cache-Aside, Write-Through patterns and Cache Stampede prevention