I'm interested in using your services, but I'm concerned about security. How does it work?

• First up, we've worked on over 250 stores so far and never had an issue, so we're quite well-versed in ensuring we look after clients' security.  Good to ask though!
• You don't need to give us your admin password.  You can, instead, add us to your store as a 'staff member', with restricted access to only certain areas if you like (we actually prefer it this way -- we only need access to certain things).  Details > https://docs.shopify.com/manual/your-store/reports/set-staff-permissions
• Within our team, we set a team password which is long and contains letters and numbers, and is unique to your store (we don't  use a generic one across all stores).  This only stays within my team, and is not shared via email.  We use a secure project management system called BaseCamp to manage all of our projects, and that is where information lives.
• Lastly, when I say our 'team' -- what I mean is, we have 4 people: Myself, Project Manager in the US, and our two developers who are based in Europe.  No-one is 'outsourced' or outside of our organisation -- everyone is part of Shopify Ninjas and reports directly to me. They have work contracts about confidentiality and security too, and we all work very closely together.