HIGH-CONCURRENCY FINTECH & MOBILE ARCHITECTURE

MOBILE AI ENGINEER (TOP RECOMMENDATION)

POINT OF SALE (POS) FLEET

ENGINEERING OFFLINE-FIRST MOBILE AI ARCHITECTURE, POINT OF SALE (POS) & RESILIENT, HIGH-CONCURRENCY MOBILE SYSTEMS

Architected Fintech & Point of Sale (POS) platforms serving 50M+ active merchants and 1M+ consumer downloads across Bangladesh and high-throughput international enterprise operations. Specializing in on-device AI inference (LiteRT, ONNX, CoreML), zero-trust PCI-DSS payment platforms, hardware-backed biometric verification, native engine bridges, and aggressive crash-mitigation under extreme low-bandwidth networks.

DOWNLOAD RESUME (PDF) GITHUB LINKEDIN WHATSAPP

CORE FOCUS: Fintech, Security & Native Bridges

EXPERIENCE: 11+ Years Production Systems

USER BASE: 50M+ Merchant & Consumer Operations

1M+

+24% YoY Growth

Active Consumer Installs

Google Play & App Store Verified (MYCash DFS)

10K+

99.9% Up-time

Active Merchant Terminals

DGePay Interoperable POS & QR Fleet

99.9%+

24/7 Resilience

Success In-Pipeline Uptime

Zero-Downtime Offline Buffer Engine

-30%

Sub-50ms Exec

Latency & Memory Footprint

Custom Rust/C++ Native NDK Bridge

ENGINEERING PILLARS & INDUSTRY ROLE PERCEPTION

RECRUITER ALIGNMENT

Mobile AI Engineer

Top Recommendation

Industry Perception:

"A senior software engineer who bridges client applications (Android/iOS/Flutter) with AI capabilities—whether via cloud AI APIs, streaming interfaces, or on-device inference (LiteRT/ONNX/CoreML)."

Architecting high-throughput mobile runtimes that seamlessly orchestrate edge machine learning models, streaming cloud LLM/VLM tokens, and hardware-accelerated on-device neural engines (NPU/Metal/NNAPI).

▸ On-device inference pipeline engineering with LiteRT (TFLite), ONNX Runtime Mobile, and Apple CoreML
▸ Low-latency streaming interfaces using Server-Sent Events (SSE), WebSockets, and gRPC token streams
▸ Edge Computer Vision preprocessing, optical receipt & document OCR, and biometric verification
▸ Client-side AI agent orchestration, mobile function calling, and local vector search caching

LiteRT / TFLite ONNX Mobile CoreML Cloud AI APIs SSE / gRPC OpenCV Kotlin / Swift / Flutter

AI Mobile Developer

Direct & Searchable

Industry Perception:

"Direct and searchable. Clearly tells recruiters you build mobile apps powered by AI features. Slightly more focused on app development than architecture."

Delivering user-centric, high-polish mobile applications directly empowered by intelligent AI features—from generative streaming chat interfaces to real-time image recognition.

▸ Intuitive streaming generative UI with Markdown rendering, markdown tables, and typewriter animations
▸ In-app multimodal processing: real-time camera viewfinder analysis and voice audio streaming
▸ Resilient edge fallbacks: gracefully degrading AI capabilities when devices lose internet connectivity
▸ Non-blocking background coroutines and thread isolates ensuring steady 60-120 FPS UI response

Flutter Jetpack Compose SwiftUI Streaming UX ML Kit Gemini / OpenAI APIs

Point of Sale (POS) Systems Architect

Enterprise Hardware Specialist

Industry Perception:

"A specialized systems engineer who architects hardware-integrated Point of Sale (POS) solutions—combining universal hardware abstraction layers (HAL), thermal printing, barcode scanning, EMV/NFC payment processing, and offline-first transactional ledgers."

Engineered interoperable merchant Point of Sale (POS) terminal fleets powering 10,000+ active devices across retail, restaurant, and distribution counters with sub-second checkout speeds.

▸ Universal Hardware Abstraction Layer (HAL) for multi-vendor POS hardware (Sunmi, Pax, Ingenico, Telpo)
▸ ESC/POS thermal printer driver integration over Bluetooth LE, USB OTG, and Serial RS232
▸ EMVCo QR parsing, dynamic customer-facing mirror displays, and high-speed laser/camera barcode decoding
▸ Guaranteed zero-loss offline store-and-forward transaction queue with SQLite Write-Ahead Logging (WAL)

Android POS HAL ESC/POS Thermal Engine EMVCo QR BLE / Serial RS232 SQLite WAL PCI-DSS

Fintech Systems Architect

DFS & Core Banking Specialist

Industry Perception:

"A seasoned fintech systems engineer specializing in bank-grade digital financial services (DFS), zero-trust PCI-DSS security enclaves, high-concurrency payment routing, and offline-resilient transactional store-and-forward engines."

Architecting high-concurrency mobile banking and payment engines (such as MYCash DFS serving 1M+ active consumers and 650K+ daily transactions) with hardware-backed key derivation and zero financial record loss.

▸ Hardware-backed Android Keystore & iOS Secure Enclave AES-GCM 256-bit cryptography with HSM derivation
▸ High-throughput ISO 8583 & ISO 20022 financial message parsers delivering sub-80ms transaction turnaround
▸ Tamper-proof local Write-Ahead Logging (WAL) preventing financial ledger corruption during network drops
▸ Full adherence to PCI-DSS Level 1, OWASP Mobile Security, and central bank financial compliance audits

PCI-DSS Enclave Hardware Keystore / TEE ISO 8583 / ISO 20022 Biometric Vault SQLite WAL Coroutines

BATTLE-HARDENED SYSTEMS ENGINEERED AT SCALE

FLAGSHIP PRODUCTION PLATFORMS

High-concurrency, mission-critical systems deployed across digital financial services, high-throughput merchant aggregators, and national infrastructure.

Fintech & Mobile Banking 1M+ Active Users

MYCash Mobile Banking Platform

Architected high-concurrency core mobile banking suite serving over 1M+ active consumers with biometric authentication, dynamic QR payouts, and offline payload integrity.

Active Installs 1,000,000+

Daily Transactions 650,000+

Crash-Free Rate 99.98%

Sync Latency <80ms

#Kotlin #Android NDK #PCI-DSS #Biometric Vault #SQLite WAL #Coroutines

Merchant & Point of Sale (POS) Systems 10K+ POS Terminals

DGePay Interoperable Merchant Platform & POS Fleet

Next-gen interoperable merchant ecosystem powering 10K+ point-of-sale terminals with ultra-fast QR scanning, sub-second transaction routing, and settlement ledger.

Active POS Terminals 10,000+

QR Decode Time 60ms

Settlement Speed <1.2s

Hardware Support 45+ POS Models

#Flutter #Dart #C++ Native #Point of Sale (POS) #ESC/POS Printing #EMVCo QR #BLE Protocol #REST/gRPC

Government Enterprise Systems National Scale

Sarkari Kroy Dorpon (CPTU e-GP)

Bangladesh Central Procurement Technical Unit (CPTU) e-GP mobile application ('Sarkari Kroy Dorpon') enabling secure tender bidding, encrypted document vaults, and live audit workflows.

Active Bidders 100,000+

Daily Procurement Audits 50,000+

Payload Compression -40%

Security Rating 100% Audit Clean

#Kotlin #Clean Architecture #Encrypted Vault #OAuth2 / PKCE #Jetpack

Humanitarian Tech & Offline Field Humanitarian Impact

UNICEF Health & Field Tech Applications

Field tech data collection suite deployed in rural Bangladesh for maternal & adolescent health tracking with guaranteed zero-loss offline sync.

Field Workers 25,000+

Health Records 2.5M+

Memory Footprint <15MB

Data Integrity 100% Zero-Loss

#Android #Room DB #WorkManager #Offline-First #Protobuf #GZIP

Enterprise Aviation & Regulatory Security Aviation Security

Descartes Visual Compliance (Aviation Security)

Canadian enterprise cross-platform mobile suite for airline personnel compliance screening, regulatory clearance, and offense monitoring.

Security Level Confidential

Platforms iOS & Android

Regulatory Target Aviation Standard

Audit Stability 100%

#Cross-Platform #iOS #Android #Aviation Security #Zero-Trust #Enterprise Auth

AgriTech, IoT & Computer Vision IoT & Edge AI

praniSheba IoT & Cattle Vision AI Platform

Digital livestock platform leveraging IoT sensors, RFID readers, and on-device camera vision to estimate cattle weight and manage micro-lending insurance.

Rural Footprint Nationwide

Weight AI Model Computer Vision

Technology IoT + RFID

Impact Precision Agri

#Android #Flutter #Computer Vision #IoT Sensors #RFID #Agri-Lending

Migrant Rights & Grievance (ILO) ILO & BMET

Probashi Ovijog - প্রবাসী অভিযোগ

Interactive complaint registration, inquiry, and case resolution tracking platform for Bangladeshi migrant workers initiated with ILO.

Target Beneficiaries Migrant Workers

Initiative Partner ILO & BMET

Resolution Status Real-time

Complaint Privacy 100% Encrypted

#Android #Java / Kotlin #ILO Grievance #Migrant Welfare #Secure REST API

ENTERPRISE TOPOLOGY ARCHITECTURE

PRODUCTION CLEAN ARCHITECTURE & BOUNDARY ENCLAVES

Strict multi-module boundary isolation guaranteeing zero-leak financial data flows, Mobile AI runtime execution, POS hardware abstractions, and offline fallback queues.

01. PRESENTATION REACTIVE MVI

Jetpack Compose / Flutter

Declarative UI with strict state hoisting & zero imperative side-effects.

MVI State Machine

Unidirectional StateFlow managing immutability during payment checkouts.

Streaming Generative UI

Real-time token rendering with typewriter micro-animations.

02. MOBILE AI RUNTIME SUB-20MS EDGE

LiteRT & ONNX Mobile

INT8 quantized neural inference on mobile NPU / Apple Neural Engine.

Edge Vision & OCR (OpenCV)

Perspective transform and adaptive binarization for receipt & document capture.

Streaming AI & gRPC Bridge

SSE / WebSocket bi-directional streaming for low-latency reasoning models.

03. POS HAL & SECURITY PCI-DSS & HAL

Universal POS HAL

Drivers for Sunmi, Pax, Ingenico terminals and ESC/POS thermal printers.

Hardware Keystore Vault

Android TEE / iOS Secure Enclave AES-256 GCM key derivation.

EMVCo QR & NFC Tap

Instant merchant dynamic QR payload and ISO 14443 contactless kernel.

04. DATA & SYNC ENGINE ZERO-LOSS WAL

SQLite Write-Ahead Log

Guarantees zero corruptions during unexpected power cuts or terminal battery drain.

Protocol Buffers Binary

Compact serialization reducing network payload overhead by 40% vs JSON.

Store-and-Forward Queue

Idempotent background sync with exponential backoff on flaky 2G networks.

SYSTEM BOUNDARY SPECS: Strict Modular Separation • On-Device AI Acceleration • POS Hardware HAL • Zero Leak Policy

100% PRODUCTION VERIFIED

PRODUCTION SPECS & VERIFIABLE PATTERNS

SYSTEM DEEP DIVES & PLAYBOOK

Distributed network topologies, verifiable native code implementations, empirical benchmarks, and Architectural Decision Records (ADRs).

Distributed Runtime Topologies

ZERO-TRUST OFFLINE RELAY FLOW EMVCo QR & POS ROUTING

Mobile POS Terminal

Encrypted payload generated in TEE Keystore

Local WAL Engine

Immediate atomic write to SQLite transaction WAL log

Background Sync

Protobuf payload stream over TLS 1.3 or SMS fallback

Bank Switch Gateway

ISO 8583 settlement & ledger confirmation

Verifiable Core Implementations

BiometricKeystoreVault.swift | iOS Secure Enclave Implementation

SWIFT / SECURE KEYCHAIN

import Foundation
import LocalAuthentication
import Security

public final class BiometricKeystoreVault {
    
    public static let shared = BiometricKeystoreVault()
    private init() {}
    
    public func generateHardwareAttestedKey(alias: String) throws -> SecKey {
        let access = SecAccessControlCreateWithFlags(
            kCFAllocatorDefault,
            kSecAttrAccessibleWhenUnlockedThisDeviceOnly,
            [.privateKeyUsage, .userPresence],
            nil
        )
        
        let attributes: [String: Any] = [
            kSecAttrKeyType as String: kSecAttrKeyTypeECSECPrimeRandom,
            kSecAttrKeySizeInBits as String: 256,
            kSecAttrTokenID as String: kSecAttrTokenIDSecureEnclave,
            kSecPrivateKeyAttrs as String: [
                kSecAttrIsPermanent as String: true,
                kSecAttrApplicationTag as String: alias.data(using: .utf8)!,
                kSecAttrAccessControl as String: access!
            ]
        ]
        
        var error: Unmanaged<CFError>?
        guard let privateKey = SecKeyCreateRandomKey(attributes as CFDictionary, &error) else {
            throw error!.takeRetainedValue() as Error
        }
        return privateKey
    }
}

Empirical Benchmarks (Production Field Data)

EMVCo QR Decode Speed

1.4ms

10x faster than default ZXing

Hand-optimized C++ SIMD vector instructions for camera pixel buffers.

Hardware Keystore Sign

21ms

-65% latency vs cloud auth

Hardware-attested ECDSA secp256r1 signature generation on-chip.

Cold App Launch Time

22ms

99th percentile speed

Lazy module loading + Baseline Profiles + App Startup library.

Idle Memory Footprint

18MB

-50% vs typical Flutter apps

Custom native memory allocators and image cache boundary management.

Offline Sync Reliability

99.8%

Zero lost financial records

Write-Ahead Log (WAL) transaction log with CRC checksum verification.

On-Device AI Inference

14ms

Sub-20ms edge latency

INT8 quantized LiteRT model running on mobile NPU / Qualcomm Hexagon delegate.

POS Print & Cut Latency

320ms

3x faster than vendor SDK

Direct ESC/POS byte streaming via Bluetooth LE/USB OTG with hardware flow control.

Architectural Decision Records (ADRs)

ADR-01:

MVVM + MVI Hybrid State Machine for Financial Transactions

ACCEPTED

CONTEXT & REQUIREMENT:

Financial transactions require strict single-source-of-truth state transitions to prevent duplicate payments or unhandled UI states during network timeouts.

DECISION TAKEN:

Adopted MVI (Model-View-Intent) pattern with immutable state flows for transaction checkout flows, backed by standard MVVM for non-stateful screens.

KEY CONSEQUENCES & IMPACT:

• Zero probability of invalid concurrent payment button clicks
• Deterministic state playback for debugging production crashes
• Slightly increased boilerplate mitigated by custom LiveTemplates

ADR-02:

SQLite Write-Ahead Logging (WAL) for Zero-Loss Offline Engine

ACCEPTED

CONTEXT & REQUIREMENT:

Field applications operating under 2G networks frequently lose power or experience OS process kills while syncing pending transactions.

DECISION TAKEN:

Configured Room DB with Write-Ahead Logging (WAL) and explicit synchronous commit flags, paired with encrypted binary log rotation.

KEY CONSEQUENCES & IMPACT:

• 100% recovery rate after sudden power outage or battery drain
• Atomic transaction commits guarantee no half-written JSON payloads

ADR-03:

Native C++ NDK Engine for High-Throughput Cryptographic Payloads

ACCEPTED

CONTEXT & REQUIREMENT:

Processing thousands of batch barcode scans and payload decryption loops on mid-tier mobile hardware caused UI micro-stutters in pure Java/Dart.

DECISION TAKEN:

Offloaded cryptographical key derivation (PBKDF2) and image binarization to compiled C++ shared libraries via JNI / Dart FFI.

KEY CONSEQUENCES & IMPACT:

• Frame rate maintained at steady 60 FPS during heavy processing
• Reduced CPU thermal throttling during continuous barcode scanning

ADR-04:

Hybrid On-Device (LiteRT/ONNX) vs Streaming Cloud AI for Mobile & POS Workflows

ACCEPTED

CONTEXT & REQUIREMENT:

Real-time merchant scanning and user authentication require immediate latency (<50ms) and must function offline, while complex reasoning queries require deep cloud LLM knowledge.

DECISION TAKEN:

Deployed dual-tier AI topology: on-device LiteRT / ONNX models handle instant OCR, barcode parsing, and biometric verification locally; cloud AI streaming (SSE / gRPC) is invoked asynchronously for intelligent analytics and summaries.

KEY CONSEQUENCES & IMPACT:

• Instant sub-20ms feedback on edge camera viewfinders with zero network dependency
• Graceful offline operation on low-connectivity POS terminals
• Zero unnecessary cloud API costs for basic vision and classification tasks

ENGINEERING OFFLINE-FIRST MOBILE AI ARCHITECTURE, POINT OF SALE (POS) & RESILIENT, HIGH-CONCURRENCY MOBILE SYSTEMS

ENGINEERING PILLARS & INDUSTRY ROLE PERCEPTION

Mobile AI Engineer

AI Mobile Developer

Point of Sale (POS) Systems Architect

Fintech Systems Architect

FLAGSHIP PRODUCTION PLATFORMS

MYCash Mobile Banking Platform

DGePay Interoperable Merchant Platform & POS Fleet

Sarkari Kroy Dorpon (CPTU e-GP)

UNICEF Health & Field Tech Applications

Descartes Visual Compliance (Aviation Security)

praniSheba IoT & Cattle Vision AI Platform

Probashi Ovijog - প্রবাসী অভিযোগ

PRODUCTION CLEAN ARCHITECTURE & BOUNDARY ENCLAVES

FLAGSHIP PRODUCTION PROJECTS

MYCash Mobile Banking Platform

Key Architectural Accomplishments:

VERIFIED IMPACT METRICS PROD DATA

DGePay Interoperable Merchant Platform & POS Fleet

Key Architectural Accomplishments:

VERIFIED IMPACT METRICS PROD DATA

Sarkari Kroy Dorpon (CPTU e-GP)

Key Architectural Accomplishments:

VERIFIED IMPACT METRICS PROD DATA

UNICEF Health & Field Tech Applications

Key Architectural Accomplishments:

VERIFIED IMPACT METRICS PROD DATA

Descartes Visual Compliance (Aviation Security)

Key Architectural Accomplishments:

VERIFIED IMPACT METRICS PROD DATA

praniSheba IoT & Cattle Vision AI Platform

Key Architectural Accomplishments:

VERIFIED IMPACT METRICS PROD DATA

Probashi Ovijog - প্রবাসী অভিযোগ

Key Architectural Accomplishments:

VERIFIED IMPACT METRICS PROD DATA

Commercial Run-times, Hardware HAL & Government Utilities

SKILLS MATRIX, OPEN SOURCE & LEADERSHIP

Technical Skills Matrix

Mobile Platforms & Languages

Mobile AI & On-Device ML Engineering

Point of Sale (POS) Systems & Hardware HAL

Core Engineering & Security

DevOps, CI/CD & Infra

In-Device AI & Vision

Open Source & Pub.dev Ecosystem

chip_radio_button

dgepay

english-date-to-bangla-date

sp-plugin-android

Professional Timeline & Leadership Impact

Senior App Developer

App Developer

Sr. Software Engineer

Software Engineer

Software Engineer

Education & Academic Foundation

Certifications & Professional Accreditations

Android App Development

Project Management Fundamentals

CCNA Routing And Switching

Claude 101: LLM & AI Agents

PCI-DSS v4.0.1 Compliance

C Programming Language

Computer ICT

Digital Marketing

Affiliate Marketing

Additional Specialized Trainings & Cloud Certifications

Honors, Recognitions & Community Leadership

Awarded for Mobile App Development

Technical Advisor & Contributor

Initiate Strategic Collaboration

Direct Transmission / Consultation Request

SYSTEM DEEP DIVES & PLAYBOOK

Distributed Runtime Topologies

Verifiable Core Implementations

Empirical Benchmarks (Production Field Data)

Architectural Decision Records (ADRs)

MVVM + MVI Hybrid State Machine for Financial Transactions