mark macdonald,
product builder
Currently building 0-to-1 experiences at Yext. Previously at Strava, Newsela, and Academia.edu.
selected projects
view all →Seshat: Echoes of History
Ask counterfactual questions of the historical record. An MCP server (9 tools) and a web app that turn the Seshat Global History Databank into something you can interrogate: pick a civilisation, inject a hypothetical, and watch a forward-projected social-complexity trajectory with confidence bands.
encore.fm
A self-hosted time-shifting proxy for live radio. Buffers any HLS stream and plays it back on a delay you set. Catch an overseas morning show while the coffee brews in your own timezone. PWA with background audio, runs on a Raspberry Pi, no accounts or cloud.
AlphabetSoup
A little app for crossword puzzlers: enter a jumble of letters and it arranges them in a circle, shuffling with smooth, spring-loaded animations to help you spot the anagram.
Style Guider
An LLM-powered copy editor that rewrites prose to match any style guide. Built on Claude, it surfaces edits inline as tracked changes you can accept or reject one by one, and stays resilient when the model returns malformed output. It’s the subject of an accompanying writeup on building robust interfaces for LLMs.
recent activity
rss →- readingThe last astronomers (opens in new tab)
- readingThe Rise and Fall of the ‘Hipster Music’ Era, 2000-2014: VICE’s Definitive Timeline (opens in new tab)
- readingEpicure: Navigating the Emergent Geometry of Food Ingredient Embeddings (opens in new tab)
- readingKarpathy said vibe coding is obsolete. What he described instead is product management. (opens in new tab)
- readingAI as a Design Medium (opens in new tab)
- listeningDAISY · rusowsky
- readingEscape from agentic loop - by David Hoang (opens in new tab)
- readingA Powerful New ‘QR Code’ Untangles Math’s Knottiest Knots | Quanta Magazine (opens in new tab)