Sterling: Cross-Platform Personal Finance Application
A unified personal finance app spanning web, iOS, and Android — built as a Turborepo monorepo with native mobile apps and a shared Supabase backend for seamless cross-device financial management.
joinsterling.com →The Challenge: Fragmented Finance Tools Across Platforms
Existing personal finance tools forced users into a compromise: either a solid web experience with no mobile app, or a mobile-only app with no desktop counterpart. Users who wanted to manage their finances across all their devices were stuck juggling multiple tools with no data synchronization.
The project required a solution that could:
- •Deliver a consistent experience across web, iOS, and Android
- •Provide native performance on mobile rather than a wrapped web view
- •Share a single backend so data stays synchronized in real time
- •Keep the codebase maintainable as a single developer or small team
Building three separate apps with three separate backends would be unsustainable. The architecture needed to be smart from the start.
The Solution: A Monorepo with Native Apps and a Shared Backend
I architected Sterling as a Turborepo monorepo containing a Next.js web application, a native Android app built with Kotlin and Jetpack Compose, and a native iOS app built with Swift and SwiftUI — all sharing a single Supabase backend.
This approach means users get the best experience on every platform: a fast, SEO-friendly web app for desktop users, and truly native mobile apps that feel right at home on iOS and Android. All financial data stays perfectly synchronized through the shared Supabase backend.
Key Features Delivered
Financial Dashboard
A comprehensive overview of accounts, balances, recent transactions, and spending trends — designed to give users a clear picture of their finances at a glance.
Transaction Tracking and History
Log, search, and review all transactions with detailed history. Filter by date, category, or amount to find exactly what you need.
Spending Analysis and Categorization
Automatic categorization of spending with visual breakdowns showing where money goes each month, helping users identify patterns and opportunities to save.
Budget Management
Set monthly budgets by category, track progress in real time, and receive alerts when spending approaches or exceeds limits.
Native iOS and Android Apps
Truly native mobile experiences — SwiftUI on iOS and Jetpack Compose on Android — delivering platform-appropriate design, smooth animations, and native performance.
Shared Supabase Backend
A single backend powering all three platforms, ensuring data consistency and real-time synchronization no matter which device a user picks up.
Technology Behind the Scenes
Sterling's architecture leverages the best tools for each platform while keeping everything manageable in a single repository:
The Turborepo architecture allows all three platforms to share configuration, types, and build tooling while each app uses the best native tools for its platform.
Business Impact: Results That Matter
Sterling demonstrates the power of thoughtful cross-platform architecture:
one app, every device, always in sync
no web-view compromises on iOS or Android
single backend reduces maintenance and ensures consistency
monorepo structure keeps three platforms manageable
By choosing native development for each platform with a shared backend, Sterling delivers the quality users expect without the engineering overhead of maintaining completely separate codebases.
Ready to Build Cross-Platform?
I build web applications, native mobile apps, and cross-platform solutions that share a unified backend — giving your users the best experience on every device.
If you need an app that works beautifully on web, iOS, and Android, let's talk. I'll architect a solution that scales — just like I did with Sterling.