Storing and organizing performance review data - SharePoint lists or something else?

At 400 employees, SharePoint capacity is not the concern; a list can hold far more records. The difficult part is maintaining confidential, per-review access as managers, reporting lines, and review cycles change. SharePoint can assign unique permissions to items, but every exception adds a security scope and ongoing administration. It also does not provide a complete performance-management process.

I would evaluate a purpose-built HR or performance platform first, with Entra ID single sign-on and documented Microsoft 365 integration. Require role-based access, manager reassignment, audit history, retention, exports, and employee lifecycle controls.

Before procurement, run a small SharePoint pilot with synthetic data in a dedicated private site. Test employee, manager, HR, and administrator roles; manager changes; terminated accounts; exports; retention labels; and reporting. Have HR, security, privacy, and records-management owners approve the design before migrating real reviews. Use SharePoint only if the pilot proves the permissions and lifecycle are supportable.