Banking
That Just Works.

Hold up a paycheck, tap deposit, wait three seconds. The money lands. We moved the read on-device with Apple’s Vision framework and Gemini Nano via AICore, with MICR + IQA validation and a server-side Check 21 re-check for the regulator. 97.3% MICR accuracy, no 24-hour review, no support ticket.

key result 420K users, $1.2B deposits

Digital banking mobile application — exhibit a / fintech-digital-banking-app

Fintech digital banking app

Industry: Fintech / Neobank
Timeline: 18 weeks
Key result: 420K users, $1.2B deposits
Stack: Kotlin + Jetpack Compose, Swift + SwiftUI, Node.js, Apple Vision framework + AFM 3 Core, Gemini Nano via AICore, MICR + IQA (X9.100-187/188), Check 21 server re-check, WebSocket, Zendesk

We built the iOS and Android apps for a US neobank that now serves 420K+ users and has moved $1.2B+ in deposits. On-device check scanning hits 97.3% accuracy, transaction uptime is 99.99%, and the store rating is a 4.7.

Jetpack Compose on Android, SwiftUI on iOS, platform-native because banking apps need to feel trustworthy. Apple’s Vision framework + AFM 3 Core handle the check read on iPhone, Gemini Nano via AICore handles it on Pixel/Android, and ML Kit is the fallback path on older devices. MICR and image-quality (X9.100-187 / 188) validation run on-device, with a server-side Check 21 re-check for legal completeness. WebSocket pushes balance updates the moment a transaction clears.

Mobile Engineering Approach

Two native apps, not one wrapper — SwiftUI on iOS and Jetpack Compose on Android, each following its platform’s design language. Banking apps live or die on feeling trustworthy.
On-device check read, server-side legal check — We ripped out the third-party vendor and replaced it with Apple’s Vision framework + AFM 3 Core on iPhone, Gemini Nano via AICore on Android, and ML Kit as a fallback. MICR + IQA pass on-device under X9.100-187 / 188; a server-side Check 21 re-check covers the regulator. Deposits went from a 24-hour review cycle to a 3-second confirmation at 97.3% MICR accuracy.
Balance updates live — WebSocket pushes every transaction as it clears. No pull-to-refresh, no stale balance at the checkout.
Security in the stack — Biometric auth, certificate pinning, encrypted local storage, jailbreak detection, and every transaction signed with a device-bound key.

The hard part

Check scanning sounds simple until you see the real data: crumpled paper, kitchen lighting, handwritten courtesy amounts, faded ink. The vendor charged per scan and still took 24 hours to come back with a “maybe”. We had to move inference on-device and build our own training loop for the edge cases off-the-shelf models keep getting wrong.

How it works

On-device check deposit

flowchart TD
  photo[Check photo] --> plat{Device}
  plat -->|iOS| ios[Vision + AFM 3 Core]
  plat -->|Pixel / Android| nano[Gemini Nano via AICore]
  plat -->|older| mlkit[ML Kit fallback]
  subgraph ondev [On-device]
    ios --> micr[MICR + IQA X9.100]
    nano --> micr
    mlkit --> micr
    micr --> ok{Image quality}
  end
  subgraph iqa [IQA failures]
    ok -->|fail| crumple[Crumpled paper]
    ok -->|fail| light[Kitchen lighting]
    ok -->|fail| hand[Handwritten courtesy amounts]
    ok -->|fail| ink[Faded ink]
    crumple --> retake[Retake in 3s]
    light --> retake
    hand --> retake
    ink --> retake
    retake --> photo
  end
  ok -->|pass| c21[Check 21 regulator path]
  c21 --> deposit[Deposit posted]
  deposit --> ws[WebSocket balance push]
  subgraph sec [Device security]
    photo -.-> bio[Biometric]
    photo -.-> pin[Cert pin]
    photo -.-> store[Encrypted local storage]
    photo -.-> jail[Jailbreak detection]
    deposit -.-> key[Device-bound signed txn]
  end
  retake -.-> loop[Training-loop edge]
  loop --> micr
  deposit -.-> speed[3s vs 24-hour vendor review]

iOS uses Vision + AFM 3 Core, Pixel uses Gemini Nano via AICore, older devices fall back to ML Kit. MICR + IQA stay the legal on-device path; crumpled paper, kitchen lighting, handwritten courtesy amounts, and faded ink ask for a retake in 3s and feed the training loop. Check 21 is the regulator path. Security is biometric, cert pin, encrypted local storage, jailbreak detection, and a device-bound signed txn. 3s versus the old 24-hour vendor review.

What changed

Check-deposit support tickets dropped 80% because users now find out in 3 seconds, not 24 hours, whether a deposit was accepted. Completion rates went up too: nobody abandons the flow waiting for a vendor review to come back.

420K+ active
users
$1.2B+ deposits
processed
99.99% transaction
uptime
97.3% scan
accuracy

Banking app dashboard showing account balances

User depositing check via mobile scanning

Kotlin + Jetpack ComposeSwift + SwiftUIApple Vision frameworkAFM 3 CoreGemini Nano (AICore)ML Kit fallbackMICR + IQA (X9.100-187/188)Check 21 server re-checkNode.jsWebSocketZendesk

“Check deposits went from a 24-hour review cycle to 3 seconds. Our customer support tickets for deposit issues dropped 80%.”