Message Center - Redesigning the messaging experience on the Grab superapp

This post details the redesign of Grab's messaging experience into 'Message Center', replacing GrabChat. It outlines the new system's architecture, comprising a message processor backend and a scalable message delivery service ('postman'). Key technical decisions include using Apache Kafka for event streaming, Amazon SQS for retries, and TCP via Hermes for low-latency, bi-directional client-server communication. The implementation of an ACK system to ensure message delivery and handle dropped connections is highlighted, along with the use of Hedwig for push notifications. The post emphasizes decoupling services, understanding requirements for extensibility, and implementing safeguards against system failures.