In the early days, the founder is also the IT department. The choices you make in the first few months are easy to make well and expensive to undo later. A little deliberate setup now saves you a painful cleanup at twenty people.
Start with identity and email
Pick one platform for email, files, and accounts (Microsoft 365 or Google Workspace) and put everyone on it. A single, central place where people sign in is the foundation for everything else, from security to adding new hires without a scramble.
Turn on the security basics immediately
Before you have anything worth stealing, you are already a target for automated attacks. The basics take an afternoon and matter from day one: multi-factor authentication everywhere, a password manager for the team, and device encryption and screen locks on every laptop. (Our cybersecurity basics guide walks through the full short list.)
Set up devices and backups consistently
Decide how a new laptop gets set up and stick to it, so your fifth hire is not configured by guesswork. And back up what matters from the start: your email and files should be backed up and restorable, not just "probably fine in the cloud".
Avoid the traps
Two early mistakes cause most later pain: tool sprawl (a new subscription for every problem until nobody knows what you pay for) and lock-in (building on something you cannot easily leave). Keep your stack small and your data portable. You can always add tools; removing them is the hard part.