SaaS

SaaS is the dominant model for business software today. The vendor hosts and operates the application, manages infrastructure, handles updates, and is responsible for uptime. You pay a subscription and use the software — you don't manage servers, databases, or deployments.

The SaaS model covers essentially every category of business software: productivity (Google Workspace, Microsoft 365), communication (Slack, Zoom), CRM (Salesforce, HubSpot), HR (Workday, Rippling), security (CrowdStrike, Okta), finance (QuickBooks Online, NetSuite), and on and on.

SaaS vs IaaS vs PaaS

The cloud delivery model spectrum:

SaaS — complete application. You manage users and data. The vendor manages everything else.

PaaS (Platform as a Service) — a platform to deploy applications on. You manage the application and its data. The vendor manages the runtime, middleware, and infrastructure.

IaaS (Infrastructure as a Service) — raw compute, storage, and networking. You manage the OS up. AWS EC2, Azure VMs, and Google Compute Engine are IaaS.

Most organizations use all three to some degree — SaaS for most business applications, IaaS/PaaS for custom workloads.

Identity and SaaS security

The proliferation of SaaS creates an identity management challenge. Each application has its own login unless connected to a central identity provider via SAML or OIDC for SSO. Managing SaaS access lifecycle — provisioning new users, deprovisioning departed ones across dozens of apps — is a real operational concern. SCIM automates this provisioning; JumpCloud and Okta are built to manage it at scale.