Moving tasks from cloud Bitrix24 to boxed with one-to-one verification

The company was moving from cloud Bitrix24 to boxed, and the entire task history — more than 2,300 tasks with conversations, files, checklists and project kanban boards — had to move with no losses. Lost conversations would have meant losing context on live work.

The cloud was not frozen: people kept working both in it and in the boxed portal with already migrated tasks. A full portal backup cannot be obtained via REST, and the cloud Drive serves chat files only to chat participants.

• Found a cloud REST trap: for tasks whose conversation lives in a chat rather than the forum, the comment export silently returns an empty list — 1,148 of 2,330 tasks were like that
• A dump → classify → stages → map → import → verify pipeline moves fields, participants, comments, attachments, checklists, results, time tracking, subtasks and groups
• Conversations are pulled from task chats and merged with forum ones without duplicates; kanban columns and group member roles are restored as in the cloud
• Large tasks are tagged into a development request backlog, the rest move as regular tasks; disputed cases are fixed by hand in CSV
• Run safety: an environment preflight, a full backup with a restorability check before writing, rollback of the database together with files, verification "gates" against losses, a memory watchdog
• A secret scanner over task text and conversations, a verify --json report; reviewed an incident where the first verification compared the dump with the boxed portal instead of the cloud with the boxed portal