Joist was initially designed with the individual contractor in mind. We may add team-based features to Joist in the future, but for now you can still use Joist within your team today.
There are a couple of ways to go about it, each with a few things to keep in mind.
Option 1: Everyone shares the same Joist account
This works if you don't expect more than one person to be using Joist at the same time. Otherwise, you could run into conflicts when, for example, two people are making changes to an invoice at the same time.
Just keep in mind, anyone who has access to your Joist account can change anything on the account, from the logo to the login email. If the login email is changed, you could permanently lose control of the account.
If you have shared your Joist account login with anyone and decide you would like to remove their access, just changed your password and they will be logged out the next time they try to access the account.
Option 2: Everyone gets their own Joist account
In this scenario, you could set each member of your team up with their own Joist account, each using a unique email address. For greater control, you may wish to setup and be the sole owner of each of the email addresses associated with the Joist accounts.
Any time you add someone new to the team you would set them up with an email address you own and a Joist account associated with that email. If someone leaves your team, just change the password and they will no longer have access to the account.
You can then login to any account at any time to access its contents.
Keep in mind that just like in option 1, whoever has access to an account can change the login email and take control of the account. What makes this option safer is that you don't risk losing everything because one team member decided to take one account over.
Both options do come with a certain amount of risk, which is important to keep in mind if you decide to try either with your team.