Back-End Developer (React Native, NestJS, AWS) at Armbrella Ltd, Remote, 1 Month, £Contract Rate

Project: Armbrella – Fitness & Wellness Social Platform

Contract duration: 1 month

Payment: Negotiable

Armbrella is a mobile platform focused on fitness and wellness that combines health tracking tools, social media features, free wellness video content, and a professional search engine for users to connect with trainers and other professionals.

The mobile application is built using React Native, while the backend services are developed using NestJS and AWS cloud infrastructure.

The platform was originally built using AWS Lambda (serverless architecture), but due to performance limitations, cold start latency, and stability issues, the application experienced delays in launch readiness.

We are now migrating the backend architecture from AWS Lambda to AWS EC2-based services to ensure better performance, reliability, and scalability for production.

The project also requires debugging and fixing issues in the existing React Native mobile application, along with improving backend stability and API performance in the NestJS backend.

Key Responsibilities

• Review the existing React Native mobile application and NestJS backend codebase
• Identify and fix bugs, crashes, and performance issues in the React Native app
• Debug and improve NestJS backend APIs and services
• Migrate backend services from AWS Lambda to EC2-based architecture
• Optimize API performance, response time, and backend stability
• Improve scalability and reliability of the backend infrastructure
• Implement proper deployment, monitoring, and logging using AWS services
• Ensure the platform is production-ready and stable before launch

Core Platform Features

• Health and wellness tracking tools
• Free fitness and wellness video content
• Social media-style fitness community
• Search engine for trainers and wellness professionals
• Mobile-first user experience through React Native

Requirements

• Strong experience with React Native mobile development
• Strong experience with NestJS backend development
• Experience working with AWS (Lambda, EC2, VPC, CloudWatch, S3, etc.)
• Experience with serverless to EC2 architecture migration
• Ability to debug complex mobile and backend issues
• Experience improving API performance and application stability
• Ability to deliver a stable, production-ready platform quickly

Goal

Deliver a fast, reliable, and scalable mobile application and backend infrastructure to support the official launch of the Armbrella fitness platform.

Job Type: Fixed term contract

Benefits:

• Flexitime
• Health & wellbeing programme
• Work from home

Work Location: Remote