Launch Ready cyber security Checklist for AI-built SaaS app: Ready for first 100 users in AI tool startups?.

What "ready" means for an AI-built SaaS app serving the first 100 users

For this kind of product, "ready" does not mean polished. It means a stranger can sign up, verify email, use the core feature, and not expose your app, your customers, or your billing stack to avoidable risk.

For an AI tool startup, I would call it ready only if all of these are true:

• The domain resolves correctly with HTTPS enforced.
• Email deliverability is working with SPF, DKIM, and DMARC passing.
• No secrets are exposed in the repo, frontend bundle, logs, or CI output.
• Authentication and authorization are tested against basic bypass attempts.
• Cloudflare or equivalent edge protection is active.
• Production deploys are repeatable and rollback is possible.
• Monitoring catches downtime before users do.
• Core pages load fast enough that early paid traffic does not leak conversion. A practical target is LCP under 2.5s on mobile for the landing page and p95 API latency under 500ms for the main app path.

If any one of those fails, you do not have a launch-ready product. You have a prototype that can lose trust fast, create support load, or burn ad spend while failing in public.

The goal is simple: get you to a safe first 100 users without turning launch day into incident day.

Quick Scorecard

| Check | Pass criteria | Why it matters | What breaks if it fails | |---|---|---|---| | HTTPS everywhere | All domains and subdomains force SSL | Prevents session theft and browser warnings | Login trust drops, mixed content errors | | DNS is correct | Root, www, app, api point to intended targets | Avoids broken routing and email issues | Users hit dead links or wrong app | | SPF/DKIM/DMARC pass | All three validate on outbound mail | Protects deliverability and spoofing risk | Signup emails land in spam | | Secrets are not exposed | No keys in repo, client bundle, logs | Stops account takeover and billing abuse | Attackers use your APIs or cloud account | | Auth cannot be bypassed | Protected routes reject unauthenticated access | Core security control for SaaS apps | Data leaks and unauthorized usage | | Role checks work | Users cannot access other users' data | Prevents cross-account exposure | Support escalations and legal risk | | Cloudflare is active | WAF/DDoS/basic rate limits enabled | Reduces bot noise and attack surface | Spam signups and uptime loss | | Deploy is reproducible | Same build can be deployed twice safely | Lowers release risk under pressure | Broken releases and rollback pain | | Monitoring alerts work | Uptime checks and error alerts notify fast | Detects failures before customers complain | Slow incident response and churn | | Backups/rollback exist | You can restore or revert within 30 minutes | Limits blast radius from bad deploys | Extended outage or data loss |

The Checks I Would Run First

1. Domain and redirect integrity

Signal: The root domain loads over HTTPS, www redirects correctly, app subdomain resolves as intended, and there are no redirect loops.

Tool or method: I check DNS records directly, test with browser dev tools plus curl, and verify Cloudflare page rules or redirect rules. I also confirm there is one canonical URL per environment.

Fix path: If redirects are inconsistent, I clean up DNS records first, then enforce canonical redirects at the edge. This prevents duplicate content issues and avoids losing signups to broken links.

2. TLS and certificate coverage

Signal: Every public endpoint returns a valid certificate with no browser warnings. HTTP requests redirect to HTTPS with no mixed content on key pages.

Tool or method: I run SSL tests against all domains and inspect the network panel for insecure assets. I also check whether third-party scripts are pulling over HTTP by mistake.

Fix path: I install or reissue certificates through Cloudflare or the hosting provider, then update asset URLs to HTTPS only. If the app still loads insecure resources after that, I remove them rather than patching around them.

3. Secret handling across codebase and deployment

Signal: No API keys appear in git history, frontend bundles, build logs, environment snapshots, or error traces.

Tool or method: I scan the repository history and deployed bundle for secrets patterns. I also review CI variables and deployment settings to make sure only server-side code touches privileged credentials.

Fix path: If a secret has ever been exposed publicly, I rotate it immediately. Then I move sensitive values into server-only env vars or managed secret storage and remove any client-side dependency on private keys.

4. Authentication and authorization paths

Signal: Unauthenticated users cannot reach protected routes; authenticated users cannot read or modify another user's records by changing IDs.

Tool or method: I test login-required pages directly by URL manipulation plus simple ID swapping in requests. I also inspect middleware placement so auth checks happen before data access.

Fix path: If route guards live only in the UI layer, that is not security. I move enforcement into server middleware or API handlers so every request gets checked even if someone bypasses the frontend.

5. Email deliverability stack

Signal: SPF passes for your sender domain; DKIM signs outgoing mail; DMARC policy exists with at least p=none during launch; signup emails arrive in inbox rather than spam.

Tool or method: I send test messages to Gmail and Outlook accounts plus use an email header checker. I verify DNS records at the registrar level because stale propagation causes false confidence.

Fix path: If mail fails authentication checks, I fix DNS records before launch traffic starts. For first 100 users I usually recommend p=none first so you can monitor without breaking delivery; then tighten policy after validation.

6. Monitoring plus rollback readiness

Signal: Uptime checks hit critical endpoints every minute; error alerts go to a real inbox or Slack channel; rollback steps are documented and tested once.

Tool or method: I simulate a failed deploy or stopped service to confirm alerts fire within minutes. Then I verify that a previous known-good version can be restored quickly.

Fix path: If you cannot answer "how do we revert this?" in under 30 seconds, launch is too early. I set up monitoring first because finding outages late costs more than fixing them early.

Red Flags That Need a Senior Engineer

1. You have Firebase/Supabase/Auth0 auth working in demos but no server-side authorization tests. That usually means the UI looks secure while direct API calls still expose other users' data.

2. Your frontend uses private keys anywhere near client code. If an AI builder placed secrets into React Native env files or bundled them into Webflow custom code blocks, assume they are compromised until proven otherwise.

3. You do not know how production deploys happen. If every release requires manual clicking across multiple dashboards with no rollback plan, you will ship mistakes under pressure.

4. Email verification is flaky. If new users miss signup emails even occasionally during the first 100-user phase, your activation rate will suffer immediately.

5. You expect bots from launch ads but have no edge protection. AI tool startups attract spam signups fast because fake accounts can abuse trials, scrape prompts, or hammer expensive endpoints.

DIY Fixes You Can Do Today

1. Remove hardcoded secrets from the repo now. Search for API keys in source files before you push anything else publicly. If you find one exposed already, rotate it immediately instead of hoping nobody noticed.

2. Turn on HTTPS enforcement. Make sure every route redirects from HTTP to HTTPS once at the edge so browsers never see mixed content warnings during onboarding.

3. Verify your sender domain. Set up SPF first if nothing else exists yet, then add DKIM signing and DMARC reporting so signup emails have a chance of landing properly.

4. Add basic rate limiting. Even a simple limit on login and signup endpoints cuts down bot noise while you prepare stronger protections later.

5. Create one rollback note. Write down exactly how you would revert yesterday's deploy in five minutes or less. If you cannot explain it clearly now, you probably need help before launch traffic arrives.

Where Cyprian Takes Over

Here is how checklist failures map to my Launch Ready service deliverables:

| Failure area | What I fix in Launch Ready | Timeline | |---|---|---| | Broken DNS / wrong redirects | Domain setup, DNS cleanup, canonical redirects for root/www/app/api/subdomains | Hours 1-8 | | Missing SSL / mixed content | Cloudflare setup plus SSL enforcement across public surfaces | Hours 1-8 | | Weak email deliverability | SPF/DKIM/DMARC configuration and validation tests | Hours 4-12 | | Exposed secrets / unsafe env vars | Environment variable audit plus secret cleanup guidance before deploy goes live again | Hours 6-16 | | Risky production deployment process | Production deployment hardening with repeatable rollout steps || Hours 8-24 | | No monitoring / silent failures | Uptime monitoring setup plus alert routing for real incidents || Hours 12-24 | | Missing handover clarity || Handover checklist covering what changed,, what to watch,,and what to do next || Hours 24-48 |

My recommendation is not to stretch this into a multi-week redesign if your goal is first 100 users. Fix the security basics first because they protect revenue now. A pretty interface with broken auth still creates support tickets,, refund requests,,and reputation damage.

• Delivery window: 48 hours
• Outcome: safe public launch posture for early user acquisition
• Primary business win: fewer launch blockers,,less support load,,and lower chance of embarrassing security mistakes during paid traffic

If your product already has traction signals but fails on any of these items,,this sprint usually pays back faster than another week of polishing features nobody can safely use yet.

References

• roadmap.sh - API Security Best Practices: https://roadmap.sh/api-security-best-practices
• roadmap.sh - Cyber Security Roadmap: https://roadmap.sh/cyber-security
• roadmap.sh - Code Review Best Practices: https://roadmap.sh/code-review-best-practices
• OWASP Top 10: https://owasp.org/www-project-top-ten/
• Cloudflare Security Docs: https://developers.cloudflare.com/waf/

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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.*