Access is granted by you, held by named individual consultants working on your project, and scoped to what the work requires. You control it through your own Zoho administration, you can see exactly what was done in your audit log, and you can revoke access at any time without asking us. Access is removed at project close unless you have an ongoing support arrangement.
Any partner can tell you their people are trustworthy. What actually protects you is that access sits in your control, is attributable to named individuals, and leaves a record you can read. Ask any partner whether they use shared logins, and treat the answer as informative.
Review the user list in your Zoho org periodically, including after any project ends. This applies to every vendor you have ever granted access to, not only to us.
For how records are handled specifically during a migration, read How does Cirro handle our data during migration?