Samrez I.

If you are building a mobile application, digital wallet, or payment-enabled product, you need an engineer who understands mobile development, payments, and real production constraints. That’s where I help. 👉 Press “Invite” or “Send a Message” to discuss your mobile app or SDK requirements before development starts. I am a Senior Mobile Engineer with 12+ years of experience, specializing in React Native, native iOS (Swift, SwiftUI), and Android development, with deep expertise in fintech, payments, and mobile payment SDKs. I have built and scaled production-ready mobile applications and SDKs for startups, scaleups, and enterprise clients across multiple regions. I have extensive hands-on experience with digital wallets, mobile POS systems, QR payments, contactless NFC, MPQR, EMV (ICC), MSR, and secure transaction flows. I have also worked on KYC, KYB, and KYI flows, ensuring secure onboarding, compliance-ready architecture, and reliable user experiences. My focus is on clean architecture, modular SDK design, performance optimization, and long-term maintainability, so teams can confidently ship, integrate, and scale. ⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻ What I Can Help You With Mobile App Development • React Native app development (iOS and Android) • Native iOS development using Swift and SwiftUI • Performance-optimized mobile applications • Fintech, wallet, and payment-enabled apps • App lifecycle, state management, and architecture design Payment & Fintech Development • Digital wallets and transaction flows • QR payments, MPQR, NFC, contactless payments • EMV ICC, MSR, and mobile POS integrations • Secure payment processing and encryption • KYC, KYB, KYI onboarding flows SDK Development (iOS & Android) • iOS SDK development using Swift • Android SDK development using Kotlin • Cross-platform payment SDK architecture • Public API design, versioning, and documentation • SDK security, error handling, and integration support Architecture & Code Quality • Clean Architecture, MVVM, modular design • React Native new architecture (JSI, TurboModules) • Dependency management and monorepo support • Code reviews, refactoring, and technical debt reduction • Unit testing, integration testing, and CI/CD readiness ⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻ Technologies & Core Skills Mobile & SDK • React Native • Swift, SwiftUI • Kotlin • iOS SDK and Android SDK development • Mobile architecture and modularization State & Data • Redux, Redux Saga • REST APIs and GraphQL • Secure token handling and session management Platform & Tooling • Xcode, Android Studio • Fastlane and CI/CD pipelines • Firebase, analytics, and crash reporting • App Store and Play Store release workflows ⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻ My Development Process 1. Requirement & Architecture Review Understand business goals, constraints, and scalability needs 2. Technical Design Define architecture, SDK contracts, and app structure upfront 3. Implementation Clean, readable, testable code following best practices 4. Testing & Optimization Performance, edge cases, and stability checks 5. Delivery & Support Documentation, handover, and long-term maintainability ⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻⸻ Why Clients Choose Me • 12+ years of real-world mobile engineering experience • Strong expertise in React Native and native iOS • Proven experience with fintech and payment systems • SDK-first mindset with scalable, clean architecture • Clear communication and realistic delivery timelines • Code that is easy to maintain, extend, and scale I don’t just build features. I build mobile systems and payment SDKs that last. If you need a senior React Native, iOS, or Android SDK engineer with real fintech and payment experience, let’s talk.