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

What "ready" means for a mobile-first AI-built SaaS app

For the first 100 users, "ready" does not mean perfect. It means a stranger can sign up on a phone, verify email, log in, use the core flow, and not expose your app, your users, or your inbox to avoidable risk.

My bar for "ready" is simple: no exposed secrets, no critical auth bypasses, DNS and email are configured correctly, SSL is valid everywhere, uptime is monitored, and the app can survive real traffic spikes without breaking onboarding or leaking data. For mobile-first apps, I also want LCP under 2.5s on a mid-range phone, p95 API latency under 500ms for the main user path, and zero broken redirects across the domain and subdomains.

If any of these fail, you do not have a launch problem. You have a security and conversion problem that will cost you support hours, ad spend, and trust.

Quick Scorecard

| Check | Pass criteria | Why it matters | What breaks if it fails | |---|---|---|---| | Domain points to production | Root domain and key subdomains resolve correctly | Users need a stable entry point | Dead links, broken signups, lost traffic | | SSL everywhere | HTTPS valid on all pages and APIs | Protects logins and session data | Browser warnings, blocked requests | | SPF/DKIM/DMARC pass | Email auth records are valid and aligned | Prevents spoofing and inbox failures | Verification emails land in spam | | Secrets are server-side only | No API keys in client bundle or repo history | Stops credential theft | Billing abuse, data exfiltration | | Auth has no bypasses | Login required where expected; roles enforced | Protects customer data | Unauthorized access | | CORS is locked down | Only approved origins can call APIs | Limits cross-site abuse | Token theft, data leaks | | Rate limits exist | Sensitive endpoints are throttled | Reduces abuse and bot traffic | Signup spam, brute force attacks | | Monitoring is active | Uptime and error alerts work within 5 minutes | You need fast detection | Silent outages, missed revenue | | Redirects are correct | HTTP to HTTPS and www/non-www rules are consistent | Avoids duplicate content and confusion | SEO loss, broken callbacks | | Mobile flow works end to end | Signup to core action works on iPhone and Android sizes | This is your actual launch path | Drop-off before activation |

The Checks I Would Run First

1. Secrets exposure check

• Signal: API keys in frontend code, `.env` values committed to GitHub, or keys visible in browser dev tools.
• Tool or method: Search the repo history, inspect built assets, scan CI logs, and run a secret scanner.
• Fix path: Move all secrets to server-side environment variables, rotate anything exposed, revoke old keys immediately, and add pre-commit scanning so this does not happen again.

2. Auth and authorization check

• Signal: A logged-out user can hit protected routes, change another user's record ID in the URL, or access admin endpoints.
• Tool or method: Manual role testing with a fresh account plus basic API requests using Postman or curl.
• Fix path: Enforce auth at the route level and object level. I would add server-side checks for every sensitive action because frontend-only protection is not real protection.

3. CORS and callback origin check

• Signal: API accepts requests from any origin or OAuth/email callbacks fail on mobile browsers.
• Tool or method: Inspect response headers and test from a different origin.
• Fix path: Restrict allowed origins to your production domains only. For mobile-first apps with embedded webviews or payment flows, I also verify callback URLs match exactly.

4. DNS and email deliverability check

• Signal: Domain resolves inconsistently; verification emails do not arrive; messages land in spam.
• Tool or method: Check DNS records at your registrar and validate SPF/DKIM/DMARC using an email testing tool.
• Fix path: Set correct A/CNAME records for root domain and subdomains. Add SPF/DKIM/DMARC before launch so password resets and onboarding emails actually work.

5. Deployment safety check

• Signal: Production build differs from local behavior; environment variables missing; migrations fail; app crashes after deploy.
• Tool or method: Compare local vs production configs; run a staging deploy; inspect logs after release.
• Fix path: Use one repeatable deployment process with locked environment variables, verified build commands, database migration order, rollback steps, and post-deploy smoke tests.

6. Monitoring and abuse check

• Signal: No uptime alerts; errors only found by users; signup forms can be hammered by bots.
• Tool or method: Review monitoring dashboards plus basic load attempts against signup/login endpoints.
• Fix path: Add uptime monitoring for homepage/API/login pages, error tracking for frontend/backend exceptions, rate limits on auth endpoints, and alerting that reaches you within 5 minutes.

Red Flags That Need a Senior Engineer

1. You find secrets already shipped to the browser

• If an AI tool put private keys into client code once, I assume there may be more hidden issues in build output or logs.

2. Users can see each other's data by changing an ID

• That is an object-level authorization failure. This is not a quick tweak; it needs careful server-side review across every model endpoint.

3. Production deploys are manual and scary

• If one wrong click can take down signup or break email verification for hours, you need someone who can make deployment boring.

4. Your app depends on multiple third-party services

• Payments, auth providers, analytics scripts, email vendors, storage buckets, push notifications: each one adds failure modes that need proper fallback handling.

5. You do not know what happens when traffic doubles

• The first 100 users may sound small until one TikTok post hits or ads start converting. If your stack has no rate limits, caching plan, or observability baseline yet I would not gamble on DIY.

DIY Fixes You Can Do Today

1. Rotate every key you can identify

• Start with database credentials, email provider keys, storage access keys, analytics tokens, and OAuth secrets.
• If you suspect exposure anywhere public-facing before now assume compromise until proven otherwise.

2. Turn on HTTPS redirects

• Force all traffic from HTTP to HTTPS at the edge.
• Make sure `www` vs non-`www` resolves to one canonical domain only.

3. Add SPF DKIM DMARC now

• This protects your sending reputation before your first signup wave.
• If you skip this step your verification emails may never reach users.

4. Test signup on two phones

• Use one iPhone-sized screen and one Android-sized screen.
• Watch for broken keyboards overlays slow buttons hidden fields weird scroll behavior and failed OTP entry.

5. Create a simple smoke test list

• Homepage loads
• Signup works
• Email arrives
• Login works
• Core action completes
• Logout works

If any one of these fails after deploy do not keep spending on traffic.

Where Cyprian Takes Over

• Domain errors -> DNS setup redirects subdomains canonical domain cleanup
• SSL issues -> Cloudflare configuration SSL validation HTTPS enforcement
• Email failures -> SPF DKIM DMARC setup sender reputation checks inbox readiness
• Secret leaks -> Environment variable cleanup secret migration rotation guidance
• Broken deployment -> Production deployment build verification rollback-safe handover
• No monitoring -> Uptime monitoring error visibility alert setup handover checklist
• Performance risk -> Basic caching edge rules static asset optimization mobile load checks
• DDoS concern -> Cloudflare protection rules rate limiting baseline hardening

My delivery window is 48 hours because launch work should be decisive. Day 1 is audit plus fixes across DNS SSL email secrets deployment health monitoring gaps. Day 2 is validation smoke testing handover documentation and making sure you know exactly what was changed so support does not become chaos later.

If I find auth bypasses serious backend logic flaws or major architecture problems I will call them out immediately because those are beyond a launch sprint fix alone. In that case I would still stabilize the release path first then recommend the next sprint for deeper remediation.

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 QA roadmap: https://roadmap.sh/qa
• Cloudflare SSL/TLS documentation: https://developers.cloudflare.com/ssl/
• Google Search Central HTTPS guidelines: https://developers.google.com/search/docs/crawling-indexing/https-in-search-results

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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.*