Freelance Mobile & Full-Stack App Developer · Available for US & remote work

Avinash Ranjan

Hire a freelance mobile & full-stack developer with 12+ years of product and service experience. I build iOS, Android, Flutter & React Native apps, web frontends, and Node.js REST/GraphQL APIs and backends—from MVP to App Store & Play Store launch.
Android (Kotlin/Java), Jetpack Compose, Retrofit, Hilt/Dagger
Flutter with platform channels and reusable SDKs
React Native & Kotlin Multiplatform (KMM)
Architecture: MVVM, MVI, Clean, Bloc/VIPER
Security: AES, SMALI analysis, penetration testing, app signing
Audio/Video: Amazon Chime, Twilio, media pipelines
CI/CD: Jenkins, GitLab, Gradle automation, Firebase
Automation: Espresso + ADB screenshot harness (58 languages)
  • Implemented payment integrations (Braintree) plus secure VPN/proxy automation with C++/JNI.
  • Delivered audio/video calling via Amazon Chime and Twilio, handling one-to-one and group sessions.
  • Hands-on with BLE/USB medical devices, offline sync, and performance tuning using profiling and LeakCanary.

What I can build for you

End-to-end product delivery—mobile, web, and backend—for startups and teams hiring a reliable freelance developer for US, remote, and global projects.

Mobile App Development

Native iOS (Swift) & Android (Kotlin/Java) plus cross-platform Flutter and React Native apps—built for performance, offline reliability, and App Store & Play Store launch.

Web Development

Responsive, fast web frontends and dashboards with React/Next.js, wired cleanly to your APIs with maintainable, well-tested code.

API & Backend

Node.js/Express REST and GraphQL APIs, secure auth (JWT/OAuth/AWS Cognito MFA), databases, and cloud deployment with CI/CD.

Delivery strengths

Leading mobile builds in fintech and healthcare, with deep work in security, automation, and media stacks.

12+ yrs

Android-first engineer delivering cross-platform apps since 2013.

Architect/Lead

Defines MVVM/MVI/Clean architectures and mentors engineering teams.

Security & media

AES/SMALI reviews, VPN/JNI, Amazon Chime & Twilio for AV flows.

Automation

Espresso + ADB tool capturing 58-language UI screenshots for quality.

Skills focus
Android Core

Kotlin/Java · Compose · Jetpack

Retrofit/Hilt, coroutines/flows, offline sync, profiling with LeakCanary.

Flutter SDKs

Platform channels · Reusable modules

Flutter banking SDKs with native bridges for device capabilities.

React Native

Native modules · Cross-platform

Delivered RN apps with native integrations and performance fixes.

KMM & Shared Code

Shared business logic

Kotlin Multiplatform for shared healthcare features.

Security & Crypto

AES · SMALI · Pen tests

Encryption, SMALI analysis, and secure signing pipelines.

Automation & QA

Espresso · Appium · MCP

58-language screenshot harness and MCP-triggered test runs.

Audio/Video & RTC

Amazon Chime · Twilio

AV calling, wake-word, and custom gain pipeline.

IoT & Hardware

BLE · USB · OBD-II

Medical device and vehicle diagnostics integrations.

CI/CD & Delivery

Jenkins · GitLab · Gradle

Release automation and guardrails for mobile apps.

Architecture & Leadership

MVVM · MVI · Clean

Technical leadership, code reviews, UML/system design.