HeartCheck

Overview

I developed the backend of HeartCheck, an AI-powered iOS app live on the App Store in Turkish and English. Users upload a chat and get an AI-generated analysis report in about a minute. I built the API with Express.js. Since AI analysis takes time, I moved it out of the request cycle and process it asynchronously with RabbitMQ queues and workers, which keeps the API fast under load. I integrated LLMs through OpenRouter and used Redis for caching and rate limiting. I also built the in-app purchase and credit system on the backend. Privacy was a core requirement, so user data is kept only as long as needed and deleted automatically. The whole backend runs in Docker containers.

I built the backend of HeartCheck, an AI-powered iOS app that analyzes chat conversations. I used Express.js, RabbitMQ, Redis, OpenRouter and Docker.