Launch Ready cyber security Checklist for AI-built SaaS app: Ready for first 100 users in B2B service businesses?.

What "ready" means for Launch Ready

For an AI-built SaaS app serving B2B service businesses, "ready" does not mean polished. It means a first 100 users can sign up, receive emails, log in, use the core workflow, and trust that their data is not exposed.

My bar for ready is simple: no exposed secrets, no broken auth paths, SPF/DKIM/DMARC passing, SSL valid on every domain and subdomain, uptime monitoring active, and the app can survive basic traffic spikes without falling over. If you cannot confidently say "a customer can pay, onboard, use the product, and support can see failures within 5 minutes," you are not ready.

For the first 100 users, the business risk is not theoretical. A bad DNS setup breaks email delivery, a missing redirect kills conversion, weak Cloudflare settings expose attack surface, and a leaked environment variable can turn into a customer data incident. This checklist is built to catch those failures before they cost you leads, trust, or days of downtime.

Quick Scorecard

| Check | Pass criteria | Why it matters | What breaks if it fails | |---|---|---|---| | Domain points correctly | Root and www resolve to production with 301 redirects | Prevents duplicate content and user confusion | Lost SEO equity, broken links | | SSL everywhere | Valid certs on root and subdomains, no mixed content | Protects login and form submissions | Browser warnings, abandoned signups | | Email authentication | SPF, DKIM, DMARC all pass | Keeps onboarding and alerts out of spam | Failed password resets and invite emails | | Secrets handling | No secrets in repo or client bundle | Stops credential leaks | Account takeover or data exposure | | Cloudflare protection | DDoS protection and WAF enabled | Reduces bot abuse and noisy attacks | Outages or signup abuse | | Environment config | Prod vars set correctly per environment | Prevents accidental test data use | Wrong API targets or broken features | | Monitoring live | Uptime checks and alerting configured | Detects outages before customers do | Silent downtime and support chaos | | Auth flows tested | Sign up, login, reset password work end to end | Core access path must be reliable | Users cannot enter the product | | Caching safe | Static assets cached; dynamic pages not cached incorrectly | Improves speed without leaking data | Stale private pages or slow load times | | Deployment rollback ready | One-click rollback or known recovery path exists | Limits blast radius of bad deploys | Long outages after a release |

The Checks I Would Run First

1. Secrets exposure check

• Signal: No API keys, private tokens, service account JSON files, or webhook secrets appear in git history, frontend bundles, logs, or deployment env dumps.
• Tool or method: Search the repo with `git grep`, scan commits with secret detection tools like Gitleaks or TruffleHog, then inspect build artifacts and browser source.
• Fix path: Rotate anything exposed immediately. Move secrets to server-side environment variables or managed secret storage. Remove client-side access unless the key is explicitly public.

2. Domain and SSL validation

• Signal: Root domain and `www` redirect cleanly to one canonical URL over HTTPS. All subdomains used by the app have valid certificates.
• Tool or method: Check DNS records at Cloudflare or your registrar. Use browser dev tools plus SSL Labs to confirm cert chain quality and no mixed content.
• Fix path: Set one canonical host. Add 301 redirects for all variants. Replace hardcoded `http://` assets with HTTPS URLs.

3. Email deliverability check

• Signal: SPF includes only approved senders. DKIM signs outbound mail. DMARC is present with at least `p=none` for observation during launch.
• Tool or method: Send test mail to Gmail and Outlook accounts. Inspect headers for SPF/DKIM/DMARC pass results.
• Fix path: Configure DNS records with your email provider. If onboarding email lands in spam now, fix this before launch because it directly affects activation.

4. Auth path sanity test

• Signal: A new user can sign up, verify email if required, log in, reset password, log out, and regain access without manual help.
• Tool or method: Run the flow in an incognito browser on mobile width and desktop width. Test with a fresh email address and a wrong-password attempt.
• Fix path: Repair broken callbacks, token expiry issues, redirect loops, and rate-limited endpoints that block legitimate users.

5. Cloudflare edge protection review

• Signal: DDoS protection is on where appropriate; basic WAF rules exist; rate limits cover login, signup, password reset, contact forms.
• Tool or method: Review Cloudflare dashboard settings plus application logs for suspicious spikes from repeated IPs or user agents.
• Fix path: Add rate limits on sensitive endpoints. Block obvious bot traffic. Keep rules narrow so you do not lock out real buyers.

6. Monitoring and incident visibility

• Signal: Uptime checks hit homepage plus critical app routes every 1-5 minutes; alerts go to email/Slack/SMS; logs show request IDs.
• Tool or method: Use uptime monitoring like Better Stack or UptimeRobot plus application logs in your hosting platform.
• Fix path: Add health endpoints for app and background jobs. Make sure failures are visible within minutes instead of discovered by customers.

SPF example:
v=spf1 include:_spf.google.com include:sendgrid.net ~all

Red Flags That Need a Senior Engineer

1. You found secrets in the frontend bundle or git history

• That is not a cleanup task only. It means you need rotation strategy plus a full audit of what those credentials could access.

2. Login works locally but fails in production

• This usually points to cookie settings, callback URLs, CORS mistakes, proxy config issues, or environment mismatch that will keep hurting conversions.

3. Emails are landing in spam or not sending at all

• For B2B SaaS this kills activation fast because users miss invites, resets, invoices, and onboarding nudges.

4. The app has multiple domains/subdomains but no clear canonical setup

• You risk duplicate sessions, broken cookies across subdomains, mixed-content errors, and confused analytics.

5. You cannot explain who gets alerted when production breaks

• If there is no owner for incidents between deploy time and customer impact time then you need senior help before scaling past the first 100 users.

DIY Fixes You Can Do Today

1. Rotate any credential you have ever pasted into chat tools

• Assume it may be copied somewhere unsafe. Rotate API keys now rather than waiting for proof of compromise.

2. Force HTTPS everywhere

• Update your domain provider so root and `www` both redirect to one secure URL using 301 redirects.

3. Check your email DNS records

• Verify SPF includes only approved senders.
• Confirm DKIM signing is enabled.
• Add DMARC even if it starts as monitoring only.

4. Turn on basic monitoring

• Add uptime checks for homepage login page API health endpoint.
• Set alerts to email plus one real-time channel like Slack.

5. Test onboarding like a customer

• Create a new account from scratch.
• Reset the password.
• Invite another user if your product supports teams.
• Do this on mobile too because many B2B buyers still open links on their phones first.

Where Cyprian Takes Over

Here is how I map failures to deliverables:

• DNS mistakes -> I fix domain records, canonical redirects, subdomains, and host routing.
• SSL problems -> I validate certificates across all live hosts and remove mixed content risks.
• Email deliverability issues -> I configure SPF/DKIM/DMARC so onboarding mail lands where it should.
• Secret leaks -> I audit env vars use site-wide then rotate exposed values safely.
• Weak edge protection -> I set Cloudflare caching rules plus DDoS protection where it helps without breaking auth flows.
• No monitoring -> I add uptime checks plus alert routing so failures are visible fast.
• Deployment risk -> I verify production deployment settings then hand over rollback notes.

The goal is not perfection; it is removing the obvious ways first-time users get blocked while keeping your support load low enough that you can focus on sales.

My recommended order is: 1. Secure access paths first. 2. Fix email second. 3. Harden edge protection third. 4. Add monitoring last so you can detect anything missed.

References

• Roadmap.sh Cyber Security Best Practices: https://roadmap.sh/cyber-security
• Roadmap.sh API Security Best Practices: https://roadmap.sh/api-security-best-practices
• Roadmap.sh Code Review Best Practices: https://roadmap.sh/code-review-best-practices
• Cloudflare Docs on SSL/TLS Overview: https://developers.cloudflare.com/ssl/
• Google Workspace Admin Help on SPF/DKIM/DMARC: https://support.google.com/a/topic/2752442

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Take the next step

If this is a problem in your product right now, here is what to do next:

• [Use the free Cyprian tools](/tools) - estimate cost, score app risk, check launch readiness, or pick the right service sprint.

• [Book a discovery call](/contact) - I will tell you honestly whether you need a sprint or if you can DIY the next step.

*Written by Cyprian Tinashe Aarons - senior full-stack and AI engineer helping founders rescue, launch, automate, and scale AI-built products.*