Theo Brandt
I am a design engineer in Copenhagen. I build interfaces for a living, mostly the parts nobody demos — the empty state, the error copy, the hundred milliseconds before a click.
Right now that means the editor at Vellum. Before that, design systems for hospital wards. In between, a lot of writing about the parts of the work that resist being turned into a process.
What I am doing nowProjects
All projectsThings I made because I wanted them to exist. A few are used by other people, which still surprises me.
-
Ledger
A double-entry accounting library with no opinions about your database.
2026
-
Halftone
A shader playground for turning photographs into printed matter in the browser.
2025
-
Casefile
Research notes for interview-heavy teams, built around the transcript rather than the tag.
2025
-
Northlight
A design system for a clinical product, where getting a colour wrong is a safety issue.
2024
Now
August 2026
Rewriting the selection model
Most of my week is inside the Vellum editor, replacing a selection model that assumed text was one-dimensional. It was not, and has not been since we added tables. This is the third attempt and the first one I believe.
The rest of the list
Say hello
I read everything and reply to most of it. Notes about something I wrote are especially welcome, particularly the ones telling me I am wrong.
theo@theobrandt.co