What is Slack enterprise search?
Slack enterprise search is a feature that extends Slack's search bar beyond Slack itself, so one query returns messages, files and canvases alongside content from connected third-party apps. Slack describes it as making "all your conversations, data, and third-party apps searchable from a single, AI-powered search bar", with results that are permission-aware and personalized to the person searching.
The architecture matters more than the marketing. Slack runs this as federated search: rather than copying your Google Drive and Confluence into a separate index, it queries those systems in real time and evaluates your access on each query. Slack states that customer data never leaves its trust boundary and that if your access to that data changes, the information stays secure.
The practical consequence of federation is that freshness is excellent and there is no re-index lag, but ranking across very different systems is harder than it is with a unified index, because the search engine has less control over how each source scores and returns results. Neither approach is simply better. They fail in different places, and the difference shows up on broad questions that span four systems rather than on lookups you already know the answer to.