Securing sensitive data in a multi-role Spring Boot application requires layering authentication, role-based authorization, encryption, and secrets management, rather than relying on any single control.
Key Points: • Authenticate every user through Spring Security before granting any access to the application. • Enforce role-based authorization so users only see or modify data appropriate to their role, using URL-level rules and method-level @PreAuthorize checks. • Encrypt sensitive data both in transit (TLS/HTTPS) and at rest in the database, so intercepted traffic or a database leak doesn't expose raw data. • Keep secrets like database credentials and API keys out of source code, stored instead in a dedicated secrets manager or vault that supports rotation. • Add audit logging around access to sensitive data, so any inappropriate access can be detected and investigated after the fact.
Example: In an HR system, an employee role can view their own salary record, a manager role can view their team's records, and only HR admins can view or edit company-wide compensation data -- enforced through role-based checks, with all salary fields encrypted at rest and every read logged for audit purposes.
Interview Tip: A concise interview answer is:
"I'd layer it: Spring Security for authentication, role-based authorization at both the URL and method level so each role only touches the data it should, TLS and at-rest encryption for the data itself, secrets kept in a vault rather than in code, and audit logging on sensitive data access so anything unusual can be traced."