Channels, threads & search
How this is scored
The daily surface: channel model, threading, mentions, files, and whether search can find a decision made eighteen months ago.
0 — Flat group chats with no threads; search covers recent messages only, and history is capped.
3 — Channels and direct messages with basic search, but threading is awkward or absent and file handling is a plain attachment list.
5 — Public and private channels, real threads, mentions and reactions, file sharing with previews, and full-text search across the whole history.
8 — Cross-organisation or guest channels with clear boundaries, message editing history, pinned and saved items, search with filters by channel, person and date, and a documented history limit or none at all.
10 — The archive is a working knowledge base: search that ranks well across years, threads that stay readable, channel lifecycle management (archive, rename, merge) without losing history, and export of a conversation in a form a human can read.
The Security Officer
Topic-based threading with move-message and resolve-topic operations is a strong daily surface, and history limits are documented rather than hidden (10,000 searchable messages on Free, unlimited on Standard). It stops short of the knowledge-base anchor because nothing evidences message-edit history, search filters, or an export a human can read — the admin export exists to seed another Zulip server. 2 3