This is a technically strong freelance opportunity that combines backend ownership with modern AWS infrastructure and real-time communication technologies. I've structured it according to your preferred recruitment template.

Project description:

Our client is developing an innovative design-to-code platform that converts Figma designs into production-ready QML code for Qt Desktop and Qt for MCUs. The solution includes a Figma plugin, a React-based live preview application, backend services, and a WebRTC signaling layer enabling fully peer-to-peer preview sessions.

Tech stack:

• TypeScript, Node.js 24, NestJS (Fastify), React 18

• Vite

• Prisma

• Redis

• Socket.IO

• WebRTC

• AWS (ECS Fargate, ALB, RDS, ElastiCache, S3, Amplify), AWS CDK

• GitHub Actions, Docker

• Sentry

• Tailwind CSS

• C++17

• Qt 6 / QML

• WebAssembly (Emscripten)

Requirements:

• Strong commercial experience with TypeScript and Node.js development

• Proven experience building and maintaining backend services using NestJS

• Hands-on expertise with PostgreSQL, Redis, and modern API architectures

• Solid AWS experience, including ECS Fargate, RDS, ElastiCache, S3, and load balancers

• Experience with Infrastructure as Code, preferably AWS CDK in TypeScript

• Strong CI/CD knowledge, including GitHub Actions and multi-environment deployment pipelines

• Experience with cloud authentication mechanisms such as OIDC role assumption

• Production-focused mindset with attention to scalability, monitoring, security, and reliability

• Experience implementing observability solutions and monitoring tools

• Strong understanding of distributed systems and real-time communication technologies

• Experience writing automated tests and maintaining high-quality CI pipelines

• Good communication skills and ability to work across backend, infrastructure, and frontend domains

• Fluent English - C1 level

Nice to have:

• Experienced in using AI tools in day-to-day workflow

• Experience with Playwright or similar end-to-end testing frameworks

• Knowledge of browser automation and CI stability improvements

• Experience with WebRTC data channels and peer-to-peer architectures

• Familiarity with OAuth2, JWT authentication, refresh token rotation, and reuse detection

• Experience with C++ and Qt/QML

• Knowledge of WebAssembly and Emscripten build environments

• Experience maintaining complex build and deployment pipelines

Main responsibilities:

• Design, develop, and maintain backend services built with NestJS, Fastify, PostgreSQL, Prisma, Redis, and S3

• Develop and enhance the WebRTC signaling server using NestJS, Socket.IO, and Redis

• Own and evolve AWS infrastructure using CDK, including ECS Fargate, ALBs, RDS, ElastiCache, S3, and Amplify

• Manage and improve CI/CD pipelines using GitHub Actions across development, staging, and production environments

• Ensure platform reliability through monitoring, health checks, rate limiting, security controls, and observability practices

• Implement and maintain distributed coordination mechanisms such as Redis-based locking

• Improve WebRTC communication reliability, including connection handling, backpressure management, and chunked file transfers

• Contribute to frontend development in React and collaborate on cross-functional product features

• Build and maintain automated unit, integration, and end-to-end test suites

• Optimize deployment workflows and support release automation processes

• Collaborate with product and engineering teams to deliver scalable and high-quality solutions

• Continuously improve platform performance, maintainability, and operational excellence