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Grab logoGrab · Feature trail

Web Chat Platform

2 posts · May 2017 – Jun 2020

What this trail covers

Grab has developed an in-house chat platform for web, enabling real-time communication between passengers and drivers during bookings, and for customer support. This involved a hybrid approach using JavaScript SharedWorker and BroadcastChannel APIs to manage multiple browser tabs and maintain a single TCP connection to the backend, overcoming the limitations of the existing unicast TCP gateway. The initial implementation focused on a simple TCP server and evolved to a service-oriented architecture utilizing Grab's infrastructure, with a client-side message handling protocol to mitigate server resource consumption and ensure message delivery reliability.

All Grab trails
  1. How We Built Our In-house Chat Platform for the WebThis post details the technical challenges and solutions for introducing a real-time chat platform on the web. It explains the limitations of the existing unicast TCP gateway with multiple browser tabs and introduces the use of JavaScript SharedWorker for managing a single OS thread across tabs and BroadcastChannel for inter-tab communication to maintain a synchronized chat experience. The implementation involves a Chat SDK that abstracts these complexities and manages the connection with the TCP service.
  2. How to Go from a Quick Idea to an Essential Feature in Four StepsThis post details the initial development of GrabChat, a real-time in-app messaging feature. It covers the problem identification (challenging internet conditions in Southeast Asia), the MVP solution development (starting with a simple TCP server and evolving to a service-oriented architecture with a dedicated message exchange service), and the evaluation of its impact on cancellation rates using statistical analysis and a cancellation prediction model. The protocol design prioritized client-side message loss handling to optimize server resources. The iteration phase highlights the addition of template messages to improve driver usability.