As data breaches become more sophisticated, security-by-design is no longer optional for SaaS applications. From OAuth2 implementation to SQL injection prevention, we cover the essentials.

**Authentication and Authorization:**
Implement robust authentication using OAuth2 or OpenID Connect. Use role-based access control to ensure users only have access to the data they need.

**Data Encryption:**
Encrypt sensitive data at rest and in transit. Use HTTPS for all communication and implement strong encryption algorithms.

**Secure API Design:**
Design APIs with security in mind. Implement rate limiting, validate inputs, and use API keys or tokens for authentication.

**Regular Security Audits:**
Conduct regular security audits to identify vulnerabilities. Use tools like OWASP ZAP to automate vulnerability scanning.

**Incident Response Plan:**
Create a comprehensive incident response plan to quickly respond to security breaches. This includes steps to contain the breach, notify affected users, and prevent future incidents.

By implementing these security measures, SaaS providers can protect their users' data and build trust in their platform.