Senior Android Developer • Mumbai

Mintoak Innovations Private Limited; Mumbai; On-site; INR 1,800,000 - 3,000,000; Full time

Job summary

Mintoak Innovations Private Limited is seeking an experienced Android engineer to design and build scalable apps using Kotlin, MVVM/MVI, and modern architecture. You will lead KMP adoption and ensure secure, high-performance networking with Retrofit/OkHttp.

You will collaborate with fintech teams on payments, ledger APIs, and analytics dashboards, while mentoring junior developers and contributing to internal tech talks.

Qualifications

• 5+ years of professional Android development with Kotlin as the primary language.

Responsibilities

• Design and build scalable Android apps using Kotlin/Java and modern architecture patterns.
• Lead Kotlin Multiplatform adoption to share logic across Android and iOS.
• Implement secure networking with Retrofit/OkHttp over HTTPS with pinning.
• Collaborate with backend teams to design APIs for ledger, reconciliation and reporting.
• Mentor junior Android developers and drive technical roadmap discussions.
• Contribute to code reviews and enforce best practices.
• Work with UX/UI to deliver pixel-perfect, accessible interfaces.
• Profile and optimize memory, battery, and startup time.

Skills

Kotlin Android

Android Architecture

MVVM/MVI/Clean Architecture

Kotlin Multiplatform

Retrofit/OkHttp

REST/GraphQL

Security/PCI-DSS

CI/CD

Cloud/Analytics

Education

B.Tech/B.E./MCA or higher

Tools

Retrofit

OkHttp

Jetpack Compose

Ktor

Firebase Crashlytics

Job description

Responsibilities

• Design and build scalable, maintainable Android applications using Kotlin/Java and modern Android architecture patterns (MVVM, MVI, Clean Architecture).
• Lead the adoption of Kotlin Multiplatform (KMP) to share business logic across Android and iOS.
• Implement secure, performant networking layers using Retrofit, OkHttp, and REST/GraphQL APIs over HTTPS certificate pinning standards.
• Integrate with payment gateways, Good to have knowledge of POS hardware SDKs (e.g., Ingenico, VeriFone, PAX), and NFC/QR payment flows.
• Own the full app lifecycle from prototyping and architecture review to production deployment on the Google Play Store.
• Build and maintain features for merchant onboarding, transaction history, real‑time settlements, and analytics dashboards.
• Implement PCI‑DSS–compliant data handling, secure storage (Android Keystore, EncryptedSharedPreferences), biometric authentication and RASP knowledge.
• Collaborate with backend teams to design APIs for ledger management, reconciliation and reporting workflows.
• Write comprehensive unit, integration, and UI tests using JUnit 5, MockK, Espresso, and Compose UI Testing.
• Profile and optimize application performance: memory, battery, CPU, and startup time.
• Conduct and participate in thorough code reviews; enforce engineering best practices and coding standards.
• Mentor 2–3 junior/mid Android developers; drive technical roadmap discussions.
• Work closely with UX/UI designers to deliver pixel‑perfect, accessible interfaces.
• Participate in sprint planning, backlog grooming, and cross‑functional architecture discussions.
• Contribute to internal tech talks, documentation, and open‑source initiatives.

Technical Skills & Experience

• 5+ years of professional Android development experience with Kotlin as the primary language.
• Deep expertise in Jetpack libraries: Compose, ViewModel, LiveData/StateFlow, Room, WorkManager, Navigation, Hilt/Dagger.
• Strong command of Coroutines and Flow for asynchronous and reactive programming.
• Proficiency with Kotlin Multiplatform (KMP) for shared business logic across platforms.
• Hands‑on experience with Retrofit + OkHttp, RESTful and GraphQL API consumption.
• Strong understanding of HTTPS/TLS, certificate pinning, OAuth 2.0, and JWT‑based authentication.
• Familiarity with Android security best practices: Keystore, ProGuard/R8, root detection, app obfuscation.
• Knowledge on CI/CD pipelines.
• Prior experience in fintech, banking, payments, or merchant services applications.
• Exposure to POS integrations, UPI/IMPS/NEFT flows, payment SDK integrations, or acquirer/issuer workflows.
• Understanding of PCI‑DSS, data encryption at rest/in transit, and audit logging.
• Proven experience with Clean Architecture, MVVM/MVI patterns, and modularisation of large codebases.
• Familiarity with dependency injection (Hilt/Dagger 2), build variants, and Gradle optimisation.
• Experience with crash reporting and analytics: Firebase Crashlytics, or equivalent.
• Proficiency with version control (Git), branching strategies (GitFlow/trunk based), and code review workflows.
• Utilize advanced developer tools like Google Antigravity and Anthropic Claude Code to orchestrate asynchronous agent workflows, handle multi‑file refactoring, and automate test generation.
• Experience leveraging modern AI‑assisted engineering tools to streamline development, accelerate multi‑file refactoring, and automate boilerplate or test generation.
• Experience with Compose Multiplatform (CMP).
• Knowledge of BLE/NFC protocols for tap‑to‑pay or smart POS device communication.
• Familiarity with Ktor or similar Kotlin‑native HTTP clients.
• Exposure to open‑source Android libraries or published apps on Google Play.
• Exposure to microservices architecture and event‑driven systems.
• Experience working with On‑Device / Local AIGemini Nano (via Android AICore) or MediaPipe.

Qualifications

BTech, B.E, MCA or higher