You will get NestJS API Development for Scalable Applications
Project details
You will get a battle-tested NestJS API that handles enterprise traffic without breaking a sweat. While most developers stop at "it works on my machine," I architect systems for production chaos: auto-scaling clusters, circuit breakers for failing services, and observability that catches issues before users do.
With 5+ years building Node.js backends for fintech, healthtech, and SaaS platforms, I specialize in the hard stuff: distributed transactions across microservices, event-driven architectures with CQRS, and zero-downtime deployments that don't wake your team at 3 AM.
My NestJS code follows Clean Architecture principles hexagonal patterns that make your API testable, replaceable, and team-friendly. No spaghetti code. No vendor lock-in. Just TypeScript excellence that scales from 1K to 1M users without a rewrite.
With 5+ years building Node.js backends for fintech, healthtech, and SaaS platforms, I specialize in the hard stuff: distributed transactions across microservices, event-driven architectures with CQRS, and zero-downtime deployments that don't wake your team at 3 AM.
My NestJS code follows Clean Architecture principles hexagonal patterns that make your API testable, replaceable, and team-friendly. No spaghetti code. No vendor lock-in. Just TypeScript excellence that scales from 1K to 1M users without a rewrite.
Programming Languages
JavaScript, Python, TypeScriptCoding Expertise
Cross Browser & Device Compatibility, Performance Optimization, SecurityWhat's included $70
These options are included with the project scope.
$70
- Delivery Time 2 days
- Number of Revisions 1
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IA
Iftikhar A.
Apr 11, 2026
REST API Integration (JSON Parsing)
Wahi built a high-performance REST API integration, reducing response time by ~ 35% with 99.9% accurate, structured weather data via /api/weather/:city. Implemented robust error handling, achieving 100% reliability for invalid requests and a production-ready backend.
AI
Arooba I.
Apr 9, 2026
Flutter UI Bug Fix
Wahi quickly resolved a Flutter UI overflow issue caused by improper ListView constraints on smaller screens. She restructured the layout using Expanded and SingleChildScrollView, ensuring proper constraint handling and smooth rendering. Clean, efficient fix with strong understanding of Flutter UI behavior.
Highly recommended.
Highly recommended.
About Wahi
Flutter & Backend Developer | iOS, Android, Firebase & AI Integration
100%
Job Success
Faisalabad, Pakistan - 7:09 am local time
Flutter Developer and Backend Engineer building iOS and Android apps with Firebase and AI integration.
App launch time under 800ms on mid-range devices. State management with BLoC keeping widget rebuilds under 5 per user action (most Flutter apps rebuild 20+ times). Firebase Firestore queries optimized to under 100 reads per screen load (preventing $500+ monthly cost spikes).
I build mobile apps and backend systems. Same developer.
What this solves is "Launch Decay" when apps ship fast but break down after 1,000 users because the architecture wasn't built for scale. State management causes UI lag. Firebase costs spike. Push notifications fail silently.
That gap doesn't exist when one person architects both mobile and backend layers.
WHAT I BUILD
Flutter Mobile Apps iOS and Android from single codebase using Clean Architecture and BLoC state management. Offline-first data handling (app works without internet, syncs when reconnected). Real-time features with WebSockets and Firebase Realtime Database. Payment integration with Stripe and in-app purchases.
SaaS Backend Systems Laravel and NestJS APIs with role-based authentication. Multi-tenant architecture where each client's data is isolated. Firebase Cloud Functions for serverless operations. REST and GraphQL APIs with proper versioning. Redis caching reducing database queries by 60-80%.
AI-Integrated Applications OpenAI API integration for chat interfaces and content generation. AI chatbots with conversation memory. LLM-powered features with streaming responses. Backend orchestration managing token costs and rate limits.
Production Debugging Apps crashing on specific Android devices (memory leaks from improper stream disposal). Firebase costs spiking from unoptimized queries. Push notifications working on iOS but failing on Android. I trace the exact cause, not the symptom.
WHY MY APPS STAY STABLE
Clean Architecture Separation between UI, business logic, and data layers. BLoC or Riverpod for predictable state management. Repository pattern isolating Firebase/API calls from UI code.
Performance Engineering Widget rebuild profiling with Flutter DevTools. Image caching and lazy loading. Firestore composite indexes on filtered fields. Apps maintaining 60fps even with complex animations and real-time data.
Built for Scale Firebase security rules preventing unauthorized reads. Database structure designed for 10,000 users, not just 100. Error tracking with Crashlytics and Sentry. CI/CD pipelines for automated testing.
Stack: Flutter · Dart · Firebase · Laravel · NestJS · Node.js · PostgreSQL · MySQL · Redis · OpenAI API · Stripe · REST APIs · GraphQL · AWS · Docker
BS Computer Science · 7+ years building mobile and backend systems · 100% Job Success
Currently working with AI-assisted development tools for faster feature delivery.
Click "Invite to Job" Flutter app, SaaS backend, AI integration, or production debugging.
Steps for completing your project
After purchasing the project, send requirements so Wahi can start the project.
Delivery time starts when Wahi receives requirements from you.
Wahi works on your project following the steps below.
Revisions may occur after the delivery date.
Design API Schema & Swagger Spec