Short notes on useful things I've learned. Inspired by @simonw and @jbranchaud.

• Multithreaded WebAssembly - 2026-03-05
• Fibonacci hashing - 2026-03-03
• Set difference vs symmetricDifference - 2026-02-24
• api-extractor - 2026-02-18
• HTTP Range requests - 2026-01-31
• Tidy Data - 2026-01-25
• One-liners for downloading media - 2026-01-10
• Protomaps and PMTiles - 2026-01-06
• V8 Natives syntax - 2025-12-23
• Monoid - 2025-12-07
• Printing V8 bytecode - 2025-12-03
• Branded types in TypeScript - 2025-11-19
• Explicit resource management - 2025-10-09
• WebAssembly library initialization patterns - 2025-10-05
• FinalizationRegistry - 2025-09-25
• Faster formatting and linting - 2025-09-17
• Lightweight TypeScript support in Node - 2025-09-09
• publishConfig in package.json - 2025-09-08
• Git exclude - 2025-09-04
• uv run - 2025-09-02
• Absolute references in spreadsheets - 2025-08-31
• Blender - 2025-08-21
• Wasm modules in Node - 2025-08-05
• Sticky regexes and the lastIndex property - 2025-07-30
• Better fast-check error messages - 2025-07-28
• Property-based tests with fast-check - 2025-07-27
• Collective action problem - 2025-07-18
• Exponentially-segmented arrays - 2025-07-16
• V8 Pointer tagging - 2025-07-11
• The HAMT popcount trick - 2025-06-26
• Debug Adapter Protocol - 2025-06-22
• Zig shadowing and builtins - 2025-06-08
• binaryen.js - 2025-05-25
• The popcnt and lzcnt instructions - 2025-05-18
• Single-pass code generation - 2025-05-04
• logrotate - 2025-04-27
• Backups with Borg and borgmatic - 2025-04-20
• Two-way sync with Unison - 2025-04-13
• Managing a Bunny CDN config with Terraform - 2025-04-06
• Gmail backups with imapsync - 2025-03-30
• Migrating from GMail to Soverin - 2025-03-23
• EU-hosted LLMs for coding - 2025-03-20
• Managing dotfiles with a bare Git repo - 2025-03-16
• Cookie banners - 2025-03-08
• Styling for print - 2025-02-26
• Castlemacs and Magit - 2025-02-21
• WebP is awesome - 2025-02-14
• Get image dimensions at the command line - 2025-02-14
• Getting started with Zig - 2025-01-22
• Lightweight multitenancy for server-side JS - 2025-01-18
• Why silicon wafers are round - 2025-01-15
• Scripting GMail with Python - 2025-01-07
• Longer V8 stack traces - 2024-11-22
• Debugging shaders - 2024-09-23
• Shader performance profiling on macOS - 2024-09-13
• Installing Python type stubs - 2024-07-17
• PyScript - 2024-07-01
• Box blur - 2024-06-30
• Curvature combs - 2024-05-23
• JAX - 2024-05-22
• Rye and Poetry - 2024-05-16
• Corner plot - 2024-05-10
• Simplex - 2024-04-28
• The symtable module in Python - 2024-03-14
• esbuild dev server - 2024-03-07
• Run-time code generation in WebAssembly - 2024-02-22
• Data race - 2024-02-17
• Authentication in Playwright scripts - 2024-02-16
• Scratch's semantics - 2024-02-07
• Pareto frontier - 2024-02-07
• Bun dev server - 2024-02-03
• Source maps in Vite - 2024-01-25
• Finding deoptimizations - 2023-11-23
• Debug options for JS libraries - 2023-11-14

• Fibonacci hashing
• Exponentially-segmented arrays
• The HAMT popcount trick
• Box blur

• V8 Pointer tagging
• binaryen.js
• The popcnt and lzcnt instructions
• Single-pass code generation

• Tidy Data
• Monoid
• Collective action problem
• Why silicon wafers are round
• Corner plot
• Simplex
• Data race
• Pareto frontier

• Castlemacs and Magit

• Protomaps and PMTiles
• Curvature combs

• Git exclude
• Managing dotfiles with a bare Git repo

• Debugging shaders
• Shader performance profiling on macOS

• Set difference vs symmetricDifference
• api-extractor
• V8 Natives syntax
• Printing V8 bytecode
• Branded types in TypeScript
• Explicit resource management
• WebAssembly library initialization patterns
• FinalizationRegistry
• Faster formatting and linting
• Lightweight TypeScript support in Node
• publishConfig in package.json
• Wasm modules in Node
• Sticky regexes and the lastIndex property
• Better fast-check error messages
• Property-based tests with fast-check
• Lightweight multitenancy for server-side JS
• Longer V8 stack traces
• esbuild dev server
• Bun dev server
• Source maps in Vite
• Finding deoptimizations
• Debug options for JS libraries

• Cookie banners

• EU-hosted LLMs for coding

• Get image dimensions at the command line

• Absolute references in spreadsheets
• Blender
• Debug Adapter Protocol

• HTTP Range requests

• uv run
• Scripting GMail with Python
• Installing Python type stubs
• PyScript
• JAX
• Rye and Poetry
• The symtable module in Python

• Scratch's semantics

• One-liners for downloading media
• logrotate
• Backups with Borg and borgmatic
• Two-way sync with Unison
• Managing a Bunny CDN config with Terraform
• Gmail backups with imapsync
• Migrating from GMail to Soverin

• Multithreaded WebAssembly
• Run-time code generation in WebAssembly

• Styling for print
• WebP is awesome
• Authentication in Playwright scripts

• Zig shadowing and builtins
• Getting started with Zig