Pre-Launch Security Checklist for SaaS MVP

Authentication and Session Management

Start with the login flow. Require strong passwords (minimum 8 characters, mix of types) and enforce rate limiting on login endpoints (e.g., 5 attempts per minute per IP). Implement multi-factor authentication (MFA) for admin accounts. Use HTTP-only, Secure, SameSite cookies for session tokens. Set session timeout (e.g., 30 minutes idle) and allow users to revoke sessions.

Example: For a Node.js app using express-session, configure:

cookie: { httpOnly: true, secure: true, sameSite: 'strict', maxAge: 30 * 60 * 1000 }

API Security and Authorization

Every API endpoint must enforce least privilege. Use role-based access control (RBAC) or attribute-based control. Validate all input: strip unexpected characters, limit payload size (e.g., 1MB), and reject malformed data. Protect against IDOR by checking that the authenticated user owns the resource.

• Use API keys or JWT for authentication, never expose secrets in URLs.
• Implement rate limiting per user/IP (e.g., 1000 requests/hour).
• Return minimal error messages (e.g., "Invalid credentials" not "User not found").

Data Protection (Encryption and Secrets)

Encrypt data in transit with TLS 1.2 or higher. Force HTTPS by redirecting HTTP requests. Encrypt sensitive data at rest: use AES-256 for database fields like passwords (hashed with bcrypt or Argon2), PII, and payment tokens. Store secrets (database passwords, API keys) in environment variables or a vault like HashiCorp Vault, never in code.

Backup strategy: Daily encrypted backups with 30-day retention. Test restoration process.

Logging and Monitoring

Log all authentication events (login success/failure), access control violations, and data changes. Include timestamp, user ID, IP, and action. Protect logs from tampering: write to a separate system (e.g., cloud logging service) with append-only permissions. Set up alerts for unusual patterns: multiple failed logins, high API error rates, or access from new geographic regions.

Example: Use structured logging (JSON) to easily search. For AWS, enable CloudTrail and set CloudWatch alarms.

Infrastructure and Deployment Security

Harden your server: disable root SSH login, use key-based authentication, keep OS and libraries patched. Run containers with minimal privileges (non-root user). Use a web application firewall (WAF) to block common attacks (SQLi, XSS). Isolate environments: separate production, staging, and development. Scan dependencies for known vulnerabilities using tools like npm audit or OWASP Dependency-Check.

Security Testing Before Launch

Run automated vulnerability scanning on your application. Test for broken access control, injection flaws, authentication bypass, and SSRF. Manual penetration testing is ideal but can be costly. For continuous testing, use a tool like Kyro (start a free scan), which hunts for real, reproducible vulnerabilities in your SaaS app and alerts you. Also consider a guide on automated penetration testing for more context.

Checklist Summary