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Tupo

My latest game project is a daily logic puzzle in the sudoku family, built with SvelteKit. There are just three simple rules: every tile gets both a number and a color; neither can repeat in a row or column; and every number–color pairing must appear exactly once.

Depending on the day/difficulty, Tupo’s board is either 4×4 or 5×5. That might seem simple, but the two interwoven dimensions make a small grid surprisingly challenging. Tupo includes weekly bonus puzzles, light and dark themes, and a colorblind mode that pairs every color with a shape.

Design, branding, and development are all mine. Tupo was released in September 2026 as an installable progressive web app. (I decided to skip the app stores on this one.)

Play Tupo in your browser here

A solved Tupo puzzle: a five-by-five grid of tiles, each with a number from 1 to 5 on one of five colors, with no number or color repeated in any row or column. A solved Tupo puzzle: a five-by-five grid of tiles, each with a number from 1 to 5 on one of five colors, with no number or color repeated in any row or column.
A Tupo puzzle in progress on a phone, with colorblind mode on: each colored tile also carries a shape, such as a circle on red or a star on yellow. Some tiles show only a number, some only a color, and a keypad of numbers and colors sits below the board. A smaller, four-by-four Tupo puzzle in progress, shown in the dark theme. Tupo’s results dialog, reading: Solved in 1:55, a perfect game, 1-day streak, with a button to copy the result as text.

Quina

Quina is a strategic, logical word game, built from scratch with Nuxt. The gameplay is based on classic pen-and-paper word games (think: Mastermind, but with words), but the app and design are 100% original.

Quina was released December 2020 as a progressive web app and on the Google Play store. Version 2.0 was released in spring 2022 (with an overhauled game board, a daily puzzle mode, and new achievements). Version 2.0 was also released on the iOS App Store.

I wrote about the original making of Quina on this blog, and on CSS Tricks. Check out Quina on the web, or download it for iOS or Android:

  • Download Quina on the App Store
  • Get Quina on Google Play

Hondo

Another word game, this one built with SvelteKit, and a bit more akin to Wordle (but with some twists and more complex mechanics).

The goal is to guess as many words as possible in a row, earning bonus points for streaks, to get to 100 points as quickly as possible.

Read about the making of Hondo, check out theGitHub repo, play Hondo in your browser, or download Hondo from the app stores:

  • Download Hondo on the App Store
  • Get Hondo on Google Play

Deno Deploy

All-new branding and interface design for Deno Deploy, Deno's serverless platform for JavaScript and TypeScript applications.

Deno Deploy logo Deno Deploy logo
Deno Deploy logo (2025)
A screenshot of the Deno Deploy dashboard, showing a list of projects under my personal organization account. The URL is console.deno.com.
The Deno Deploy app dashboard
A screenshot of the Deno Deploy 'Create a new application' page, showing options to choose a GitHub repository, set an app name and deployment targets, alongside an app config panel, routing details, and a map of selected regions. A screenshot of a Deno Deploy sandbox detail page, showing a running sandbox with its CPU time, memory time, wall clock time, and HTTP request count, plus a list of sandbox events.

Dactyl

Interface design, landing page design, and branding for Dactyl, a platform for building real, native iPhone, iPad, and Android apps using AI.

Apps run live in an in-browser simulator as the agent builds them, and can be installed on real devices. Dactyl also helps with publishing to TestFlight and the app stores.

Dactyl logo Dactyl logo
Dactyl logo (2026)
A screenshot of the Dactyl homepage, headlined 'Build real iPhone apps just by describing them,' with a prompt box mid-typing and a stack of iPhones running example apps, the front one showing a book tracker.
The Dactyl.dev homepage
A screenshot of the Dactyl builder, showing an agent conversation about refining a workout timer app on the left, and the finished app running live in an iPhone simulator on the right, with colorful run, recover, and sprint interval cards.
The Dactyl builder: an agent conversation on the left, and the resulting app running live in the simulator
A loading animation using the Dactyl mark

Other recent design work

A selection of logos, illustrations, animations, interfaces, and other design work from recent work history.

Deno logo Deno logo
Deno logo since 2024
Claw Patrol logo
Logo for Claw Patrol, a secure firewall for agents.
A screenshot of the Claw Patrol homepage, headlined The missing option between babysitting and YOLO mode, with the tagline The security firewall for any agent, an install command, and an isometric stack of integration logos.
Claw Patrol homepage
A screenshot of the Claw Patrol analytics dashboard, showing request counts, latency charts, and top routes for an agent's traffic.
The Claw Patrol analytics dashboard
An illustration in the style of lo-fi anime showing a cute dinosaur coding on a laptop in a cozy room. The laptop has a Deno sticker on the lid, and there's a steamy mug of coffee beside it. In the background is a plant, on the sill of a window overlooking hills and trees. It's dusk outside, with some stars visible in the upper skies, and it is raining gently as clouds slowly float past. The interior is warmly lit by a single desk lamp. On the desk is a takeout box, with chopsticks and a lemon beside it. Peeking over the edge of the box, barely visible, is DeeDee, the Deno Deploy mascot. Ferris, the Rust mascot, can also just barely be seen peeking out from inside the plant pot.
Animated illustration for Deno.com
Interactive dino customizer for the Deno 2.0 launch
JSR logo
A screenshot of JSR.io, the JavaScript package registry.
JSR.io - the JavaScript package registry
A screenshot of JavaScript.tm, the site to free JavaScript from Oracle's trademark.
JavaScript.tm - campaign to free JavaScript from Oracle's trademark

CSS Easing playground

Created for this blog post, this interactive playground lets you examine how a variety of easing curves look and feel, and allows you to draw up your own and copy the CSS.

Every curve on the page is an SVG, including the interactive demo, which is accessible across device types. The curve redraws in real time as the handles are moved, and an animated node follows the curve to demonstrate the movement.

joshcollinsworth.com/demos/easing

SvelteKit static blog starter

A fully open-source, pre-configured starter for a SvelteKit blog. Includes Markdown and CSS preprocessing; has mdsvex with rehype plugins pre-installed; and includes automatic prefetching of top-level routes, an RSS feed, and a JSON API.

(Admittedly, this project is a little less relevant now that SvelteKit offers most of this stuff when you set up a new project, but the boilerplate remains useful for those who want a quick start.)

sveltekit-static-starter.netlify.app

CodePen Collections

A couple of CodePen collections showcasing some of my favorite pens and experiments, along with some pens that are more about a laugh than the code.