Slack
Slack was originally built primarily in PHP, and as it scaled the team began migrating performance-sensitive parts of the backend toward Hack, the PHP-derived language and runtime created at Facebook.
What we cover in the quiz
- Slack was originally built on PHP, and as the service grew, the engineering team began migrating performance-sensitive parts of the backend toward Hack, the PHP-derived language Facebook created.
- Slack adopted Hack and the HHVM runtime, both originally built at Facebook to make PHP-style code run faster, as a way to keep scaling its existing codebase rather than rewriting it in an unrelated language.