Developer's Guide to Privacy Compliance

Privacy compliance isn't just a legal concern — it's an engineering challenge. This guide helps developers understand privacy requirements and build compliant systems from the ground up.

Privacy by Design

Privacy by Design is a GDPR requirement that means building privacy protections into your systems from the start, not bolting them on after the fact. The seven foundational principles are:

1. Proactive, not reactive — prevent privacy issues before they occur
2. Privacy as the default setting
3. Privacy embedded into design
4. Full functionality — positive-sum, not zero-sum
5. End-to-end security — full lifecycle protection
6. Visibility and transparency
7. Respect for user privacy — user-centric design

Data Minimization in Practice

Only collect data you actually need. This isn't just a legal requirement — it reduces your attack surface, simplifies compliance, and builds user trust.

Practical tips:

• • Audit every field in your sign-up forms — do you really need date of birth?
• • Use anonymous or pseudonymous identifiers where possible
• • Implement automatic data retention and purge policies
• • Avoid logging PII in application logs
• • Use aggregated analytics instead of individual tracking where possible

Implementing Consent Management

Consent must be freely given, specific, informed, and unambiguous. Here's how to implement it properly:

• • Use granular consent options (not a single "agree to all" checkbox)
• • Record consent with timestamp, version, and scope
• • Make withdrawal as easy as giving consent
• • Don't use pre-checked boxes or dark patterns
• • Implement cookie consent banners that actually block cookies until consent is given
• • Honor Global Privacy Control (GPC) browser signals

Encryption and Security

Both GDPR and HIPAA require appropriate security measures. At a minimum:

• • In transit: TLS 1.3 for all connections. No exceptions.
• • At rest: AES-256 encryption for databases and file storage.
• • Application-level: Encrypt sensitive fields (SSN, health data) at the application layer.
• • Key management: Use a KMS (AWS KMS, GCP KMS, HashiCorp Vault). Never hardcode keys.
• • Hashing: Use bcrypt or Argon2 for passwords. Never store plaintext.

Access Control and Data Isolation

Implement the principle of least privilege:

• • Role-based access control (RBAC) for all data access
• • Row-level security in databases for multi-tenant applications
• • Audit logging for all access to personal data
• • Automatic session timeouts and re-authentication for sensitive operations
• • Separate production and development data — never use real PII in dev/staging

Engineering for Data Subject Requests

Your architecture must support DSR automation. Design for these capabilities from the start:

• • Data inventory: Know where all personal data lives across your systems
• • Data export: Build APIs that can extract all data for a given user in a structured format
• • Data deletion: Implement soft-delete with hard-delete capabilities. Handle cascade deletion across related records.
• • Data correction: Support updating personal data across all systems
• • Consent tracking: Record and enforce consent preferences across services

API-First Privacy Compliance

An API-first approach to privacy compliance means every compliance operation can be triggered, monitored, and audited programmatically. Benefits:

• • Integrate compliance checks into CI/CD pipelines
• • Automate DSR processing across microservices
• • Build privacy dashboards from real-time data
• • Trigger compliance workflows from application events
• • Generate compliance reports programmatically

PrivaBase is built API-first. Every feature is accessible via REST API, making it easy to embed privacy compliance directly into your development workflow.

Common Developer Privacy Mistakes

• Logging PII: Application logs often contain personal data. Implement log scrubbing or avoid logging PII entirely.
• Using PII in dev: Use synthetic data or anonymized datasets for development and testing.
• Ignoring third-party SDKs: Every SDK and third-party service that processes user data needs review. Many tracking pixels and analytics SDKs send data to third parties.
• Cookie consent theater: Consent banners that don't actually block cookies until consent is given are non-compliant.
• No data retention: Data accumulates indefinitely if you don't actively purge it. Set retention policies and automate enforcement.