We publish this project without the brand name, by agreement with the client. The data in the screenshots is demo data (balances, transactions and the account were generated for display); no real financial data is used.
01 · The idea and the goal
A wealthy person's assets are scattered: several banks in different countries, a brokerage account, crypto on exchanges and in wallets, gold bars, an apartment that's rented out. To see how much capital they have in total and how it's changing, they have to reconcile statements and exchange rates by hand. The idea behind the app is to do this automatically: connect your sources once and see your up-to-date net worth at any moment, in a single currency.
The goal: build multi-currency wealth tracking where balances are pulled from banks and exchanges via API, currency, crypto and metal prices update on their own, transactions are sorted into categories and budgets, family members or a financial advisor can get shared access, and statements can be imported and reports exported. All of it as a mobile app for iOS and Android, a backend with bank integrations and a web admin panel.
02 · What was hard
- Bank integrations across regions. There's no universal "connect a bank": for some countries it's Plaid, for Europe it's Salt Edge, and certain banks have their own providers. Each comes with its own OAuth, account and transaction formats, webhooks and re-authorization. We had to normalize them into a single "account — balance — transactions" model so that every bank source looks the same in the app.
- One net worth from different asset classes. Banks in euros, a brokerage account in dollars, crypto in coins, gold in ounces, real estate at a manual valuation — all of it has to be converted into one currency at current rates and added up. Fiat, crypto and metal prices come from different sources and update on a schedule, and everything is recalculated on the fly when the base currency changes.
- Brokers and crypto exchanges. Investment accounts connect through SnapTrade, crypto exchanges through CCXT (a unified interface to dozens of exchanges), and wallets are read by their blockchain address. Balances arrive asynchronously and update in real time over WebSocket, so the portfolio stays live without manual refreshes.
- Money demands care and privacy. JWT authentication, rate limiting, bank tokens stored on the server, separation of permissions. Team access (family, accountant, advisor) comes with granular permissions and approvals: a member sees only the wallets and assets they're allowed to, and some actions go to the owner for confirmation.
- Import, categories and reports. Not everything connects via API, so there's CSV statement import with format detection, manual assets and trades, a system of categories and subcategories, budgets and spending analytics, plus report export for yourself or your advisor.
The core engineering challenge: turn a dozen incompatible sources (banks in different countries, brokers, exchanges, wallets, metals) into one live net worth in the currency of your choice.
03 · How the app works
Total net worth and assets
The main screen shows total net worth in the base currency, its trend, an exchange-rate widget and a list of wallets. Each wallet expands into assets: bank accounts (connected via API), crypto with coin amounts, a brokerage account, metals in ounces, real estate. You can see how much each asset contributes to the total.
Transactions, budget and analytics
Transactions are pulled from connected accounts or added manually, and sorted by category, bank, cash and crypto. On top of that sit analytics and budgets: income and expenses for the period, net cash flow, a comparison with last month and a spending breakdown by category.
AI concierge
The built-in AI assistant answers questions about your finances using portfolio data: it analyzes how your wealth is structured, points out risks and growth opportunities, and breaks down spending. It sits on top of the same data as the rest of the app — so its answers reflect the user's real financial picture.
04 · The result
The result is a full-fledged fintech product: a mobile app, a backend with bank integrations and a web admin panel. The app covers total net worth across all assets, bank and exchange connections via API, multi-currency conversion at live rates, transactions with categories and budgets, spending analytics, team access with approvals, an AI concierge, CSV import and report export. It's built for iOS and Android from a single React Native (Expo) codebase.
Under the hood, balances and transactions are pulled from banks (Plaid, Salt Edge), brokers (SnapTrade) and crypto exchanges (CCXT), normalized into one format and stored in PostgreSQL; currency, crypto and metal prices update on a schedule, and portfolio changes reach the app in real time over WebSocket. The backend and admin panel are packaged in Docker behind nginx.
05 · What's next
The product is moving toward deeper wealth analytics: net worth history and returns by asset class, goals and scenarios, new banking providers and regions, and an expanded AI concierge. The unified "source → account → assets → transactions" model makes it possible to add new integrations without rewriting the app.
React Native (Expo) on the client and Node + PostgreSQL in Docker on the server, with Open Banking providers, SnapTrade and CCXT, make a scalable foundation for fintech apps: it's easy to extend with new data sources, currencies and platforms.