Non-production environments are where sensitive data most often leaks. Keep developers productive while protecting PII, PCI, and sensitive information by combining data minimization with robust, automated controls. Start by separating duties and identities across production, staging, and development environments. Grant the least-privileged access with role- or attribute-based rules and log every read. Mask or tokenize direct identifiers (names, emails, PANs) and perturb quasi-identifiers to preserve statistical properties while protecting individual privacy. When real data is unnecessary, generate synthetic datasets that retain distributions and referential integrity. Rotate credentials with a secrets manager, forbid hard-coded keys, and scan repos and pipelines to prevent drift. Prefer ephemeral sandboxes spun up from versioned snapshots, and enforce egress controls to block unapproved exports. Finally, automate evidence: data classification tags, policy checks in CI, and reconciliation reports so audits pass without requiring fire drills.