Security Basics Every Product Team Should Ship With

Security is a product feature. Ship a baseline from day one to protect users and avoid costly emergencies later.

1) Secure authentication & session management

• Password hashing: never store plain text; use bcrypt or Argon2.
• Token storage: web → HTTP-only, Secure cookies (avoid localStorage for tokens).
• Short-lived access + refresh rotation: rotate refresh tokens on use.
• MFA: at least for admins/sensitive actions.
• Lockout/rate limit: throttle repeated login failures.

2) Input validation & sanitization

• Validate on the server (Joi, Zod, class-validator).
• Sanitize to prevent injection/XSS; avoid string-built queries.
• Validate outputs for critical integrations.

3) Secure communication (TLS/HTTPS) & headers

• Force HTTPS; enable HSTS; use modern TLS suites.
• Apply Helmet (CSP, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy).

4) Least privilege & RBAC

• Scope service permissions minimally.
• Enforce roles/permissions on every API and UI action.
• Separate internal vs public APIs; restrict access paths.

5) Rate limiting, throttling & abuse protection

• Per-user/IP limits on public endpoints (login, reset, search).
• Captcha or progressive delays for signup/login abuse.
• Prefer upstream enforcement (gateway/proxy) where possible.

6) Configuration & secrets management

• Do not commit secrets; use env vars or secret managers.
• Encrypt in transit and at rest; rotate keys regularly.
• Use least-privilege service accounts.

7) Dependency & supply-chain security

• Audit (npm audit, Snyk) and patch promptly.
• Pin versions; remove unused or vulnerable packages.
• Fail CI on critical vulnerabilities.

8) Logging, monitoring & incident readiness

• Structured logs (JSON) with context: request/user IDs, IP, route.
• Alert on anomalies: spikes in 401/403/5xx, traffic bursts.
• Maintain an incident playbook (breach, data leak, key leak, rotation steps, contacts).

9) Data encryption & classification

• Encrypt/hash PII and sensitive fields; consider field-level encryption/tokenization.
• Mask sensitive data in logs.
• Classify data (public/internal/confidential) and enforce handling rules.

10) Reviews, threat modeling & audits

• Threat model at design time (actors, entry points, trust boundaries).
• Security code reviews before release; periodic pen tests.
• Re-run security tests routinely to catch regressions.

From my projects

Marketplace: RBAC (buyer/seller/admin), HTTP-only cookies, rate-limited login/search, dependency audits. Clinic voice assistant: encrypted logs, restricted access via secure APIs, regular key rotation.

Start here , quick checklist

• Add server-side validation/sanitization to one endpoint.
• Force HTTPS + Helmet.
• Enable rate limits on login.
• Remove console.log in production builds.
• Run a dependency audit and patch one critical item.