React Native Engineer | Full-Stack Developer
Kamal Khastagir
Cross-Platform Mobile App Developer & Full-Stack Engineer building AI SaaS & Mobile Apps
View My WorkAbout
About Me
I'm a Full-Stack Mobile Engineer and React Native Developer with 3+ years of experience building high-performance iOS and Android applications alongside Next.js and NestJS backends. Currently, I work on a production SaaS platform, specializing in AI SaaS Integration and Multi-Provider LLM Orchestration (Anthropic, OpenAI, Gemini).
My core expertise lies in building complex Real-Time Systems and implementing Offline-First Architecture with robust Data Synchronization strategies. I have hands-on experience with native device capabilities like Geolocation/Google Maps API, Camera Integration, and deep performance tuning through Gesture Handling (Animated API) and Xcode Configuration.
I'm passionate about the entire product lifecycle — from Schema Design and Authentication Hardening to iOS/Android Build Automation. Whether it's configuring In-App Purchases / Payment Gateways or architecting a distributed backend, I take a structured approach to problem-solving, moving ideas from prototype to production seamlessly.
Work
What I've Worked On
Version-Controlled Artifact Storage
Added versioned S3 key tracking with on-demand upload and fallback resolution, cutting generation latency and covered with full-stack parity tests.
Multi-Provider LLM Abstraction
Unified Anthropic, OpenAI, Gemini, and Azure OpenAI behind a singleton client layer, normalising token usage across streaming and non-streaming paths.
Automated PDF Report Generation
Built rich, data-driven PDF exports — trend charts, revenue projections, competitor data — solving real pagination and layout edge cases.
Two-Token Session Architecture
Implemented access/refresh token session management with silent refresh-and-retry on expiry across a large Redux-Saga codebase.
Real-Time Messaging & Presence
Built WebSocket-powered chat with match-based session unlocking and live delivery for a social discovery app.
Invite & Referral Funnel
Built a cookie-based invite flow with edge middleware, threading invite state through pricing, CTAs, and onboarding without exposing it in the URL.
Location-Aware Discovery
Implemented proximity-based recommendation UI with swipe gestures, maps integration, and a coin-based premium unlock economy.
Security Hardening
Applied anti-enumeration patterns on auth endpoints, validated third-party SDK responses, and sanitised LLM-generated HTML/CSS to prevent XSS.
Admin Tooling & Observability
Built internal admin dashboards with Redis-cached stats, secure credential bootstrapping, and normalised logging across services.
Projects
Selected Work
LeanPath
AI-Powered Diet & Fitness App. A privacy-first, cross-platform mobile application that generates customized 7-day AI diet and workout plans, featuring advanced weight tracking graphs, Razorpay payments, and Google AdMob monetization.
DigiQuick AI
AI SaaS Integration platform for generating digital products. Features Multi-Provider LLM Integration, dynamic Performance Optimization, and Authentication Hardening.
Otiumx – AI Journaling
AI-powered journaling app built with React.js. Features Real-Time Systems synchronization and secure user data management with careful Schema Design.
React Native Applications
Cross-platform mobile apps demonstrating Offline-First Architecture, robust Data Synchronization, Gesture Handling (Animated API), and Deep Linking.
Delux Caterer Website
Business website for a real catering company based in my hometown, Kolkata, with over half a decade in the trade. Built with Next.js and SEO optimisation, deployed on Vercel.
Skills
What I Work With
Mobile Development
- React Native & React Native CLI
- Native Modules (iOS/Android)
- Cross-Platform Development
- Custom Native Components
Core Languages
- TypeScript
- JavaScript (ES6+)
- HTML5
- CSS3
State & Data Fetching
- Redux Toolkit
- TanStack Query (React Query)
- Zustand
- Context API
Offline-First & Storage
- Offline-First Architecture
- SQLite & MMKV
- Background Sync
- Local Caching
APIs & Real-Time
- RESTful APIs & GraphQL
- Socket.io & WebSockets
- Real-Time Systems
- Push Notifications (FCM)
Backend & Database
- Next.js & NestJS
- Node.js & PostgreSQL
- Redis & Firebase
- Multi-Provider LLM Integration
Deployment & Native Tooling
- Xcode & TestFlight
- App Store & Play Console Deployment
- Git, GitHub Actions, CI/CD