Topic Notes
Notes around things I come back to often: Linux, networking, Docker, APIs, servers, debugging, deployments, and small infra details.
Start with the problem you are trying to solve. If you already know which tool you need, find it in the tool guides.
- API Testing
Using OpenAPI files, mock responses, webhooks, gRPC testers, and request tools without copying blindly.
- Browser Debugging Utilities
Device info, network info, key codes, microphones, cameras, JavaScript playgrounds, and browser-side testing.
- Browser File Tools
Small browser-side file tasks such as zip creation and Base64 conversion, with privacy boundaries.
- Browser Games and Practice Tools
Small browser games and practice utilities that live under tools without becoming blog posts.
- Calculators and Unit Conversion
Percentages, discounts, loans, interest, unit prices, currency, temperature, fuel economy, number bases, and roman numerals.
- Dates, Timestamps, and Time Zones
Dates, durations, timestamps, time zones, age calculations, stopwatches, and ETA estimates.
- Debugging CORS Without Guessing
A practical way to reason about CORS errors, preflight requests, credentials, and browser behavior.
- Docker Basics
Dockerfiles, Compose conversion, logs, and the small container details that matter during development and ops.
- Email Debugging
Email headers, normalized addresses, suspicious messages, and the limits of what email metadata can prove.
- Filtering Docker Logs Effectively
How to filter Docker container logs without losing useful context, timestamps, and failure clues.
- HTTP and API Debugging
Requests, headers, auth headers, status codes, curl, MIME types, and small checks before blaming the API.
- IDs and Test Data
UUIDs, ULIDs, generated MAC addresses, and safe fake identifiers for tests and examples.
- Indonesian Data Formats
NIK, phone numbers, spelled numbers, local salary estimates, maps links, and Indonesian text checks.
- Linux Command Line Tasks Without Surprises
Practical notes for find, grep, sed, xargs, chmod, cron, and other commands that are easy to misuse.
- Network Debugging Notes
DNS, WHOIS, IP addresses, ports, subnets, MAC addresses, Wi-Fi QR codes, and SSH tunnels.
- Nginx Reverse Proxy Configuration
Common nginx reverse proxy configuration patterns, headers, upstreams, TLS, and debugging checks.
- Practical Image Tools
Image compression, format conversion, metadata removal, redaction, QR codes, placeholders, stickers, and watermarks.
- Reading Logs Before Searching Randomly
Parsing logs, preserving context, checking timestamps, and narrowing down failures before random searching.
- Security and Cryptography Basics for Developers
Hashing, encoding, signatures, keys, passwords, tokens, and crypto terms developers often meet while debugging systems.
- SQL Formatting and Test Data
Formatting SQL, generating inserts, and preparing small data sets for review or testing.
- Testing and Debugging WebSockets
How to test browser WebSocket connections, inspect frames, and think about proxy-related failures.
- Testing Regex Before Shipping It
How to test matching and replacement patterns before using regex in real code or shell commands.
- Text Formatting and Cleanup
Case conversion, line formatting, text statistics, Unicode, binary views, emoji, NATO spelling, and message formatting.
- Understanding and Debugging JWTs
How to read JWT headers and claims, check expiry, and understand what signature verification does and does not prove.
- Web Metadata
Meta tags, Open Graph previews, UTM links, and the page data used by browsers, crawlers, and social apps.
- Working With Configuration Files
Reading, sorting, and editing configuration files without moving comments or changing meaning.
- Working With PDFs
PDF metadata, page extraction, merging, signatures, and browser-side document handling.
- Working With Structured Data
JSON, YAML, TOML, XML, CSV, JSONPath, schemas, diffs, viewers, and format conversion caveats.
- Working With URLs
Parsing URLs, encoding query strings, reading slugs, and checking redirected or wrapped links.
- Writing and Publishing Text for the Web
Markdown previews, HTML entities, slugs, URL encoding, and simple publishing tasks.