Gusto is a software platform for payroll, benefits and HR administration, aimed at small and mid-sized businesses and startups. It processes payroll, supports employee onboarding, and handles the enrolment and administration of health, dental and vision insurance. Retirement plans and workers' compensation insurance are offered through partners. Gusto is delivered online as a service, and it also provides an API that other companies can use to build integrations.
Gusto is a US company with headquarters in San Francisco and Denver, and it is privately held. As a US provider it is subject to US law, including the CLOUD Act. According to Wikipedia, Gusto serves customers in the United States only, and the service is built around US payroll and tax rules. For a European organisation it is therefore mainly relevant as a reference point or for a US subsidiary. There is no self-hosted option and the software is not open source.