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Bankacı

An iOS, Android and web app for loans, credit cards, deposits and investments, with a loan marketplace that connects borrowers with bankers.

Web (Open web version)App Store (Open iOS version)Google Play (Open Android version)
built by
Burak Altıntaş
released
February 2025
platform
iOS, Android, web
tech
React Native, Go, Next.js, TypeScript, Expo, PostgreSQL, Google Cloud Run, Claude (Anthropic), Swift (App Intents, WidgetKit), Kotlin, RevenueCat
Bankacı screenshot

Overview

Bankacı started as a loan calculator for bankers who price loans and for people looking for one, and both still use the same calculation engine. A banker works out the loan before the meeting and sends the result to the customer in one tap; the borrower sees the instalment and the total cost before signing. The app now covers credit cards, deposits and investments as well.

The product has four parts: the iOS and Android app, bankaci.app, a web portal on bankaci.app, and KrediBul (kredibul.bankaci.app), which connects borrowers with bankers. bankaci.app also offers the app to estate agencies and car dealerships, so they can work out housing and vehicle loan instalments with their customers. The app has been on the App Store since February 2025, and the current iOS version is 4.5.0, released in November 2026.

Problem

In a branch, loan figures are usually worked out on the bank's own screen. Comparing payment plans, checking the legal limits and sending the customer a proper document are separate jobs. On the borrower's side, the instalment, the taxes and the total cost often stay unclear until the signature. Rates, deposit offers and card campaigns are spread across each bank's own site.

What It Does

  • Nine calculators: personal (consumer, vehicle, housing), business (instalment, spot, revolving, cheque and bill discounting), mortgage refinancing, how much you can borrow for a given instalment, overdraft and credit card, deposit (term deposit and daily-earning account), early repayment, savings finance, and investment (eurobonds, government bonds and T-bills, funds).
  • Seven payment plans: standard, prepaid interest, equal principal, custom/balloon, grace period, increasing and decreasing instalments. KKDF and BSMV taxes are included.
  • Legal limits: the banking regulator's (BDDK) term and loan-to-value limits and the central bank's (TCMB) maximum overdraft and credit card rates appear in the calculation, each with its legal basis.
  • Car value for vehicle loans: the car is picked from the TSB kasko (insurance value) list, and the legal loan and term limits follow from its value.
  • Rates the banks publish: the banks' loan and deposit pages are read once a week, and the rates and offers are shown with their source. Tapping one opens the calculator with that rate, and loan and deposit results are compared with the banks' rates.
  • Credit cards and campaigns: a card center lists the banks' card campaigns and a card catalog, with search and filters. Members add the cards they use to My cards (up to 20, no card number asked) and can get a notification or an email when those cards have new campaigns. The card section is free. The home screen also shows featured bank campaigns, which you apply for on the bank's own site.
  • Investments: the investment calculator fills in fund prices from TEFAS and bond prices from TCMB. Premium members keep their funds in My funds and get a monthly email about them.
  • PDF and sharing: results go out as a PDF or an image. A banker's PDF ends with their request link and QR code; without a link, and with contact details added, it ends with a WhatsApp QR.
  • For bankers: a permanent request link; one inbox for leads from the link, the pool and campaigns; the KrediBul pool; and publishing their own campaigns.
  • WhatsApp import: a banker shares a customer's WhatsApp messages, photos or PDFs to Bankacı. ID, tax and phone numbers, IBANs and card numbers are masked on the phone, the message is read once, and the matching calculator opens already filled in.
  • Document check: Premium bankers can have the documents that came with a request, or ones they upload, checked for signs of editing. The result is there to help the banker decide; the decision stays with them.
  • For borrowers: one request on KrediBul and applications to bankers' campaigns.
  • Two AI assistants: describe the case to the Loan AI Assistant in a sentence and it suggests the right calculator and plan. The Investment AI Assistant puts a term deposit, a daily-earning account, T-bills, funds and eurobonds side by side for an amount and a period, and makes no recommendations or forecasts. In both, the numbers come from the app's own calculation engine.
  • Siri: say "Calculate a loan with Bankacı" (in Turkish, "Bankacı ile kredi hesapla") and Siri asks for the amount, term and rate, then reads out the monthly instalment and the total repayment (iOS 17 and later).
  • Widget and notifications: a home screen widget on iOS and Android, a weekly rates email and notifications. The app is in Turkish and English.
  • Premium: monthly, yearly and lifetime plans, with a 7-day free trial on monthly and yearly. A member who brings in three friends gets three months of Premium.

Technical Highlights

  • Mobile: Expo, React Native and TypeScript. Swift App Intents for Siri, WidgetKit and SwiftUI for the iOS widget, Kotlin for the Android widget and in-app updates. Shares from WhatsApp arrive through a share extension on iOS and a share intent on Android. On an unfolded iPhone Duo the app switches to two columns, with Home on the left and the open page on the right. The calculations are covered by Jest tests.
  • One calculation engine: the TypeScript calculation code is the same in the app and the web portal, so both give the same numbers. Siri runs the same engine inside JavaScriptCore instead of a Swift copy.
  • Backend: Go with only the standard library's net/http for HTTP, and PostgreSQL (Neon). Sign-in with an email code.
  • Web: bankaci.app and KrediBul are server-rendered Next.js. Every page exists in Turkish and English, with structured data, a sitemap and llms.txt. The web portal is React with Vite.
  • Infrastructure: Google Cloud Run, Cloud Build with separate test and production environments, Cloud Scheduler, and a database backup that is restored and checked every day.
  • AI: Anthropic's Claude runs both assistants, the weekly reading of the banks' loan and deposit pages, WhatsApp import and Document check. Page text goes to Claude with a strict JSON schema; pages that draw their rates with JavaScript go through a separate headless Chromium service. A deposit reading that differs from the approved version waits for my approval before it goes live.
  • Other services: RevenueCat for subscriptions, Expo Push for notifications, Resend for email, AdMob for ads.
  • Privacy: calculations run on the device. Calculation events carry no name, phone number or email. For signed-in members, app opens and usage counts are kept with the account, for analytics only. Text typed to the assistants or read from WhatsApp has ID and tax numbers, phone numbers, IBANs, card numbers and emails masked before it is sent.

My Role

  • Product idea, scope and design
  • Mobile app (React Native, Swift, Kotlin)
  • Go backend and database
  • bankaci.app, KrediBul and the web portal
  • Google Cloud infrastructure and release pipelines
  • App Store and Google Play releases