I designed a novel event sourcing solution for the Vapor backend. Every change in a space is recorded as an immutable event, which buys the classic event sourcing benefits: full replay, analytics, easier debugging, retroactive features, and a data model that stays future-proof as the product evolves.
Recurring chores, bills, and events are powered by a custom recurrence engine built on RRULE, the recurrence-rule standard from the iCalendar spec (RFC 5545) that underpins most calendar systems.
The day-timeline view is a from-scratch layout engine that recreates the native iOS calendar's look and behavior, including correct placement of overlapping events, purpose-built for embedded, view-only use inside the app.
The backend is structured around Swift actors and modern Swift concurrency, keeping shared state safe without a tangle of locks.
Swift macros cut boilerplate across features, targeted dependency forks fill gaps where libraries fell short, and automation scripts handle local setup and service orchestration.
The codebase is modular enough that a second product, Hellopost, was assembled from the same foundation and reached the App Store ahead of RoomAid itself. How that foundation is kept coherent across several products at once is written up on the blog, in "The operating system behind a five-product portfolio."