Saqlain AminHome / Learn
Guides, articles & video courses
Things I've made to help other people learn — reference guides and cheat sheets, longer articles on Medium, and full video courses on YouTube, covering web development, operating systems, computer architecture and assembly language. All of it is my own work, and free.
Guides & cheat sheets
Reference guides I wrote for SADEVZ
Part of a set of 20+ practical guides that ship alongside the free SADEVZ Tools — written to be useful on their own, each linking into the relevant tool where it helps.
Regex Cheat Sheet
Character classes, anchors, quantifiers, groups, lookarounds and ready-to-test patterns.
DeveloperJSON Cheat Sheet & Common Errors
Valid vs invalid examples, the trailing-comma trap, and how JSON differs from a JS object.
ImagesJPG vs PNG vs WebP
A practical guide to which image format to use and why, with real compression numbers.
SecurityJWT Anatomy Visual Guide
Header, payload and signature — what a JSON Web Token actually contains.
DeveloperUUID Visual Guide
The anatomy of the string, and how v1, v4, v5 and v7 differ in randomness and ordering.
DeveloperEncoding Cheat Sheet
Base64, URL encoding, HTML entities and UTF-8 — what each is for and when to reach for it.
DataJSON vs YAML vs XML vs CSV
The same dataset in four formats, with the trade-offs of each.
SecurityPassword Security Cheat Sheet
Recommended length, entropy, hashing and what actually makes a password strong.
DesignColor Formats & Accessibility
HEX vs RGB vs HSL, and how to check contrast for accessible interfaces.
Articles
On Medium
Longer-form articles on web development, operating systems and computer architecture — written to explain the hard bits with simple, worked examples.
Tailwind CSS Tutorial for Beginners
A step-by-step guide, including installation and your first styled components.
Operating Systems · MediumYou Don't Understand Synchronization Yet?
The critical-section problem explained from scratch with one clear example.
Operating Systems · MediumPeterson's Solution, Explained Simply
The classic two-process synchronization solution walked through with an easy example.
Operating Systems · MediumHardware Synchronization
How Test_and_Set() and Compare_and_Swap() atomic instructions build locks.
Digital Logic · MediumHalf Adder & Full Adder
Truth tables, logic diagrams and Boolean functions for both adders.
Computer Architecture · MediumY86 Instruction Set Architecture
An introduction to the Y86 ISA used in computer-systems courses.
Video courses
On YouTube
Full lecture-style playlists for computer-systems topics, taught the way I teach them in class.
COAL — Computer Organization & Assembly Language
A full course on how computers are organised and how assembly maps to hardware.
Playlist · YouTubeY86 Instruction Set Architecture
Working through the Y86 ISA step by step — instructions, encoding and execution.
Playlist · YouTubeAssembly Language Course
Assembly language from the ground up, with worked examples throughout.
Original research
Benchmarks
Measured, reproducible benchmarks rather than received wisdom — on image formats and PDF compression.
Elsewhere
- The SADEVZ Blog — team writing on development, design and technology.
- Stack Overflow
Work with me
If something here was useful and you'd like the same clarity applied to your product or your learning, get in touch.