Show HN: Qwiz – Building a daily global quiz app with synchronised leaderboards

Ello HN! I just shipped Qwiz after a few weeks of solo development.

It's a daily trivia game where everyone worldwide gets the same 10 questions each day and competes on a global leaderboard.

Interesting technical challenges I solved:

Global Synchronisation: Ensuring all players worldwide get questions at exactly the same time across timezones. Used CloudKit with scheduled functions and local timezone calculations.

Question Management: Built a content pipeline to manage 15k+ questions across 10 categories with difficulty balancing, duplicate detection, and fact-checking workflows.

Real-time Leaderboards: Handling concurrent score submissions from thousands of users while maintaining accuracy. Implemented optimistic updates with conflict resolution.

Analytics Engine: Custom system tracking performance across categories, improvement over time, and global statistics without compromising privacy.

Performance: Keeping the app snappy while handling complex scoring algorithms, offline capabilities, and seamless syncing when back online.

What I learned:

Global time coordination is MUCH harder than I expected. Trivia question quality control and making sure its balanced and fair is surprisingly complex Users care more about consistent daily habits than feature complexity CloudKit's eventual consistency model required creative workarounds

Tech stack: SwiftUI, CloudKit, custom backend for question management, Core Data for offline support.

The app has 8 additional game modes (word puzzles, math challenges, etc.) but the daily global challenge is the core hook.

Would love feedback from the community! Happy to answer questions about any of the technical implementation.

LINK - https://apps.apple.com/gb/app/qwiz-daily-quiz-trivia-fun/id6...