Eventy
There are way too many events at Waterloo, and manually adding everything to Google Calendar got old fast. So I built Eventy as a personal tool to scan pages and turn them into calendar-ready events.
The biggest thing I learned was that sending entire pages straight to an LLM is usually a bad move. It costs more, runs slower, and can miss obvious details. I started doing a preprocessing pass first so the model sees the useful parts, plus table rows converted into structured snippets when schedules are buried in messy markup.
From there, I used structured output for the event fields, handled timezone conversion, and wired the extension flow so it feels stable in normal use: clear scan states, caching, and a quick upcoming vs past review before adding events. It started as something I made for myself, but I kept polishing it, and now it has dozens of users.