Engineering @ Facebook: Facebook Chat. The new Facebook Chat uses Comet (long polling with a hidden iframe) against a custom web / chat server written in Erlang, designed to handle a launch to all 70 million users at once. It was tested using a “dark launch” period where live pages simulated chat request traffic without showing any visible UI.
Recent articles
- My review of Claude's new Code Interpreter, released under a very confusing name - 9th September 2025
- Recreating the Apollo AI adoption rate chart with GPT-5, Python and Pyodide - 9th September 2025
- GPT-5 Thinking in ChatGPT (aka Research Goblin) is shockingly good at search - 6th September 2025