jordan

@jdan.me

13543 Followers 1056 Following

Author of the critically-acclaimed "Harry Potter" series of children's fantasy novels

Languages chart showing Lean 50.0% and Ruby 50.0%, represented by equal gray and dark red segments.
A small Palm OS Emulator window showing the HotSync app. The screen has “Welcome.” near the top, tabs labeled “Local” and “Modem,” and a central sync icon with red and blue arrows above the label “Cradle/Cable.” At the bottom are “Log” and “Help” buttons.
A wooden cabinet displays 3D-printed Tokyo train station badge decorations: a stand with U 02, JB 07, JY 29, and T 01 signs, plus separate JY 01, Z 01, and U 15 pieces.
a grid of 3D Hanzomon line icons on a 3D printer, showing text like Z15 within a purple circle
side-by-side Left: Figma showing a photograph of a Nakano station exit sign next to a vectorized version of it. The text on it reads "North exit" "South exit" Right: A preview of the design in a 3D modeling CAD tool
a 3D print of an exit sign at Nakano station in Tokyo, Japan. A downward facing arrow sits atop “North Exit” and “South Exit” labels
a hotel room. on top of the bed are two screenshots overlapping each other. (1) a screenshot of codex desktop (2) The cover of Design Patterns: Elements of Reusable Object-Oriented Software To the right of the bed is a red chair facing the bed
A screenshot of https://web.archive.org/web/20120501201929/http://twitter.github.com/bootstrap/ Bootstrap, from Twitter The landing page from 1 May 2012
A modular stamp made of small wooden rectangles. The front of the stamp is shown with MTWTFSS at the top, followed by the numbers 1-31 arranged in a grid.
Smart cards in Japan interoperation Map showing a wide array of IC card carriers (Suica, Nimoca, Rapica, Luluca) and their incredible mix of interoperability
Screenshot of a dark-mode Notion workspace called “Japan Metro / Lines.” The left panel shows a table of train lines with columns for Name, Visited percentage, and Num Stops; “(Fukuoka) Nanakuma” is selected, alongside lines like Airport, Asakusa, Chiyoda, Ginza, and Marunouchi. The right panel shows the “(Fukuoka) Nanakuma” page with a table of 18 stations from Hashimoto to Hakata, including station names, stop numbers, place names, sign icons, and visit status tags such as “Entered/Exited” and “Passed thru.” The two Fukuoka stations at the top have a "Visited" score of 100%
a mirror selfie of a man wearing a striped button down shirt and khakis. to the left is a makeup mirror placed to reflect the photographers face back at the camera. at this distance the face is heavily distorted
Studied 103 cards in 13.37 minutes today (7.79s/card)
Anki Wrapped summary graphic on a dark blue, starry background. Text reads: ‘Reviews: 24,773,’ ‘Minutes Reviewed: 2,411,’ and ‘Cards Created: 1,535.’ A ‘Top Decks’ list shows: 1) Ultimate Geography, 2) Tutoring, 3) Vocabulary, 4) Vocabulary, 5) Vocabulary. On the left side is a tall vertical mosaic of small squares forming a gradient from dark blue at the top to teal at the bottom. The bottom displays the text ‘ANKIWRAPPED.COM.'
the lazy vim welcome screen, with banner text レイジーヴィム with some options beneath
Counting Paths in Directed Acyclic Graphs: Solutions to Advent of Code 2025 Day 11 Jordan Scales December 11, 2025 Abstract We present efficient algorithms for counting paths in directed graphs with and without constraints. Part A addresses the unconstrained path counting problem from node you to out, while Part B extends this to count paths from svr to out that must visit both dac and fft. The key insight that enables efficient computation is recognizing the input graph as a Directed Acyclic Graph (DAG), allowing dynamic programming with memoization to reduce exponential complexity to linear time.
an Anki card showing 敬老の日 on the front, and images of the elderly on the back with an example sentence
movie poster for clerks
An email Subject: Jordan <> Alexander Graham Bell From: Alexander Graham Bell <agb@yahoomail.com> to: me Hi Jordan, Any interest in inventing the telephone with me? We have early prototypes but could use your help -- agb
end credits for Spooky Express
NYC Mayor Race on polymarket, with Yes selected. A bit of $1 pays out $1,000
a desktop computer with a number of windows 1. Figma with "spritsheets" of Japanese input for Pokemon Blue and The Legend of Zelda for inspiration 2. A console output for `bin/banner サーティワン` and ASCII art style output 3. A pixel editor for the katakana character ェ 4. The neovim editor for a file called "katakana.rb" with the following code visible: XE = AnsiShadow::Glyph.from_mono <<~TEXT.chomp ████████ ██ ██ ██████████ TEXT XYO = AnsiShadow::Glyph.from_mono <<~TEXT.chomp ████████ ██ ████████ ██ ████████ TEXT Dakuten = AnsiShadow::Glyph.from_mono <<~TEXT.chomp █ █ █ █ TEXT
## # Returns the pixel at (px_x, px_y), or nil if it # is out of bounds # # @param [number] px_x # @param [number] px_y def pixel(px_x, px_y) # NOTE: In ruby, arr[-1] is the last element of the row, so we # include an explicit check to reduce footguns return nil if px_x.negative? || px_y.negative? @grid[px_y] && @grid[px_y][px_x] end
the neovim editor with lazyvim editing ansi_shadow_spec.rb # frozen_string_literal: true RSpec.describe AnsiShadow::Text do it "recalls characters" do char = AnsiShadow::Text.new <<~TEXT x x xxx TEXT expect(char.to_s).to eq <<~TEXT.chomp █ █ ███ TEXT end end the font is a large mono-space Comic Sans, and the explorer on the left has a label in Katakana エクスプロール
a chess mat on a light wooden table
a genki textbook opened to a table of japanese te-form conjugations. on a computer screen behind the book is an anki flash card for 書く and書いて the caption “at the mind gym” is placed on top
a white man in a traditional japanese robe standing next to a rack of CDs
A screenshot of https://github.com/ruby/ruby/commits?author=dhh showing "No commits history" on ruby/ruby for github user dhh
A screenshot of thingdle showing the following results Transitdle #20 3/6 ⬛🚙⬛🚙⬛ 🚎🚙🚎🚋🚋 🚋🚋🚋🚋🚋 The title is set to "Transitdle #20 3/6" The available emoji are: ⬛🚙🚎🚋
a still from Googlebox showing pete and sophie reacting to a weekly show
An AIM away message composer, the away message reads Hello again(newline) (indent) to all my friends (newline) (indent) together we can play (newline) (indent) some rock n' roll the background is the album art for Scary Monsters n Nice Sprites