Backend Developer for Mobile Conversational App

Job ID: 40158631

Budget: $15 – $25 USD

I’m preparing a private-beta, mobile-first web app designed for short, real-time conversational interactions using voice and text. The front end is largely in place; I’m looking for an experienced backend developer to help build a reliable, low-latency, serverless backend on AWS.

The backend will support:

Event-driven AWS Lambda functions behind API Gateway

Ingestion of voice and text input, with integration to a third-party language processing API

Session-based conversation handling with automatic expiration

Structured, predictable responses returned to the client

Privacy-conscious logging suitable for debugging and iteration

Internationalisation-ready payloads (UTF-8, language metadata, no hard-coded strings)

This is not a massive-scale system; the emphasis is on reliability, clarity, and UX-sensitive behavior, rather than raw throughput. Thoughtful error handling, retries, and graceful fallbacks matter more than premature optimization.

I’m looking for someone comfortable working with AWS Lambda and API Gateway, who has experience integrating external APIs into real-time flows, and who values clean interfaces and maintainable systems. Clear documentation and test coverage are important, as this project will evolve through hands-on beta testing.

Deliverables

Infrastructure-as-code setup (SAM, CDK, or equivalent) deployable to my AWS account

End-to-end working backend supporting a basic voice/text conversation flow

Session persistence across refresh with defined expiration behavior

Logging that preserves traceability without exposing sensitive user data

Clear README explaining configuration and extension points

This engagement is focused on the backend and AWS infrastructure only; the frontend is handled separately. I like to work with clear milestones and brief check-ins, just so we both know things are on track and can adjust early if needed.