As a business with many contractors, which identity and access management tools simplify onboarding and offboarding securely?

We ask the same underlying question in different ways.

• As a business with many contractors, which identity and access management tools simplify onboarding and offboarding securely?
• We have a large number of contractors and need a secure way to automate their access provisioning and deprovisioning. What IAM solutions handle this well?
• We have a large number of contractors and need an IAM solution that automates their onboarding and offboarding processes securely. What do you recommend?