Hacklang at Slack: A Better PHP

This post details the migration to Hacklang, a superset of PHP, to improve developer productivity through better tooling, a stronger type system, and static type checking. It highlights the benefits of static typing for catching bugs early, the use of gradual typing for incremental migration, and the introduction of 'shapes' for representing complex data structures. The post also discusses the advantages of async/await for concurrency and the decision to break PHP compatibility to enable Hack's growth.