reddit-map-posts-app

A Devvit app that adds a new kind of post to a subreddit: a Map Post. The author drops pins on an interactive map and picks the area it frames; anyone scrolling past can read it, but only the author can edit it. Moderators can also publish an Index Post that lists every map on the subreddit.

Most of the design work went into the fact that Reddit renders the same post twice - inline in the feed, where it gets a fixed slot and isn't allowed to respond to gestures, and full screen, where it owns the device. Both are the same page asking at load which one it is. The decisions behind that, and a dozen others, are written up as ADRs in the repo.

TypeScript, Devvit, MapLibre, OpenFreeMap

Source available on Github.