Backend Development: Built scalable Node.js (NestJS, Express) services and RESTful APIs for mobile and web clients.

Architecture: Designed backend architecture on PostgreSQL and MongoDB for performance, scalability and security.

Integrations: Integrated third-party APIs and services: OAuth (Google, Apple, Facebook, GitHub), IAP, push, analytics.

DevOps: Docker, CI/CD on AWS and GCP; owned features from development to production.

Mobile & Web: Built React Native / Expo and Next.js apps for iOS, Android and Web.

Real-Time: Implemented Socket.IO features across backend and mobile/web clients.

Team Leadership: Led the team, ran code reviews and set engineering standards.

Code Quality: Jest tests, strict TypeScript and OpenAPI-generated typed API clients.

AI Tools: Daily use of Claude, Codex and Cursor to speed up delivery and code review.

STACK: Node.js, NestJS, Express, TypeScript, PostgreSQL, MongoDB, REST API, OpenAPI Codegen, Socket.IO, Docker, CI/CD, AWS, Google Cloud Platform, Firebase (FCM, Analytics), React Native, Expo (EAS, Router), React, Next.js, Tailwind, Redux Toolkit, Zustand, TanStack Query, React Hook Form, Zod, Reanimated, FlashList, MMKV, React Native IAP, Auth (Google, Apple, Facebook, GitHub), Jest, React Native Testing Library, Sentry, Datadog, Fastlane, Feature-Sliced Design, Claude/Codex/Cursor.

Backend: Built Node.js (Express) REST APIs for React and React Native apps.

GraphQL: Designed PostgreSQL schemas and GraphQL APIs with Hasura and Apollo.

Serverless: Built Firebase Cloud Functions for business logic and webhooks.

Payments: Integrated Stripe, subscriptions via Qonversion and React Native IAP.

Web Frontend: Responsive React / Next.js UIs with Tailwind and reusable components.

Third-Party SDKs: Integrated OneSignal, AppsFlyer, IronSource and AppLovin.

STACK: Node.js, Express, REST API, TypeScript, PostgreSQL, Hasura, Apollo GraphQL, Firebase Cloud Functions, React Native, Expo, React, Next.js, Tailwind, MobX, Redux-Saga, Stripe, Qonversion, RN IAP, OneSignal, AppsFlyer, AppLovin, IronSource.

Mobile Application Support: Maintained and supported existing applications.

Game Porting: Ported mobile games to React Native Web.

Game Development: Created new mobile games from scratch.

Web Application Development: Supported and enhanced web applications.

Analytics Integration: Implemented tools like Facebook, Firebase, and Amplitude.

STACK: React Native, React Native Web, React, React-Navigation, Next.js, Redux, Redux-Thunk, Lottie Animation, AsyncStorage, Facebook, Amplitude, Firebase.