Hinterland

The problem worth solving

Every music festival has an app, and most of them are useless at the festival. They are built like websites: fetch the schedule, fetch the artist, fetch the map. Then 15,000 people walk into a rural valley in St. Charles, Iowa, the towers saturate, and the one app you installed specifically for this weekend spins forever.

I built Hinterland on the opposite assumption. There is no network. Everything else follows from that one decision.

What that decision actually cost

It is easy to say "offline-first" and ship a cache. Committing to it means the full four-day schedule, every artist bio, all 48 pieces of artist artwork, the festival's four maps, the vendor directory and eleven years of past lineups are compiled into the app and work in airplane mode.

The network became an enrichment layer instead of a dependency: set-time changes, the forecast, crowd ratings, and Apple Music top songs. Every one of them caches what it fetches and falls back to what is already on the phone. Nothing in the app has a loading state that can strand you.

That is the part I would defend in an interview. The hard call was not the caching — it was refusing to let any primary surface depend on a request.

Building the weekend

The app earns its place before the gates open and during the sets:

• My Lineup — star sets to build a personal schedule, with automatic detection of overlapping sets, so the app tells you what you are actually choosing between rather than letting you star two things at 9pm and find out in person.
• Reminders — local notifications 5 to 60 minutes before your starred sets. Scheduled on-device, so they fire with no signal. A push-based reminder would have been simpler to build and would have failed at exactly the moment it mattered.
• Widget and Live Activity — "Up Next" on the Home Screen and Lock Screen, and the set you are watching in the Dynamic Island from 90 minutes out, counting down on its own.

Details that come from having been there

Food & Drink groups all 33 stands by where they are actually parked — East, West and South Concourse, VIP, GA+, Basecamp, the mobile carts — because "which stand" is never the question. "What can I reach from here" is. Combinable filters cover vegetarian, vegan, gluten-free, dairy-free, nut-free and sugar-free.

Maps bundles the grounds, concourse, driving and shuttle-parking maps as pinch-zoomable artwork, and georeferences the grounds map through MapKit so the blue dot shows where you are standing on the festival's own map, not on a generic one.

Weather pulls a WeatherKit forecast for the amphitheater itself. Severe and extreme National Weather Service advisories break out to the top of the schedule, and every set on an artist's page shows what the weather will be doing while they play.

Past lineups goes back to 2015 — every headliner, every full bill, day by day. Bundled, so it settles the argument about who played 2017 with no signal.

Making a solo app feel social

Sets can be rated one to five stars once they are under way. Ratings work offline and upload later, and scores pool through CloudKit so every set carries the average everyone else gave it — while your written notes stay on your phone. It is a shared layer that costs no backend to run and degrades to a purely local feature when CloudKit is unavailable.

When the last set ends, the Schedule tab becomes the weekend's recap: how many sets you saw and for how many hours, your best of the festival, the day you gave the most to, and the festival's best sets according to everyone who rated one — shareable as a rendered card. Then the year joins the archive, and the app has a reason to exist in November.

What this project demonstrates

Shipping a real iOS app across the modern Apple surface area — SwiftUI, WidgetKit, ActivityKit, CloudKit, WeatherKit, MusicKit and MapKit — with a single architectural constraint enforced consistently through all of it. Project generation via XcodeGen so there is no .pbxproj to conflict on, and a documented capability setup where every missing entitlement degrades to a named, explained fallback rather than a silent failure.