Launch Ready cyber security Checklist for founder landing page: Ready for security review in marketplace products?.

What "ready" means for a founder landing page security review

For a marketplace product, "security review ready" does not mean perfect. It means a reviewer can open the landing page, verify the domain and email setup, confirm the site is served over HTTPS, and find no obvious signs of unsafe deployment, exposed secrets, broken redirects, or weak email authentication.

If I were assessing this for launch, I would want to see these outcomes:

• The primary domain resolves cleanly with one canonical URL.
• HTTP redirects to HTTPS with no mixed content warnings.
• Cloudflare is in front of the site with DDoS protection and caching enabled.
• SPF, DKIM, and DMARC all pass for the sending domain.
• No secrets are present in client code, public repo history, or build output.
• Monitoring is live so you know within 5 minutes if the page goes down.
• The page loads fast enough to avoid looking broken or suspicious. A good target is LCP under 2.5s on mobile.

For marketplace products, security review usually fails on boring things: bad DNS records, missing email auth, leaked API keys, insecure forms, or a deployment that exposes staging data. That is why I treat launch readiness as a production safety check, not a design polish task.

Quick Scorecard

| Check | Pass criteria | Why it matters | What breaks if it fails | | --- | --- | --- | --- | | Domain ownership | Domain points to the correct production host | Reviewers need to verify the real product | Wrong brand trust, failed verification | | HTTPS only | All traffic redirects to HTTPS with valid SSL | Prevents interception and browser warnings | Mixed content errors, blocked forms | | Cloudflare in front | Proxy enabled with DDoS protection on | Reduces attack surface and absorbs abuse | Direct origin exposure, downtime risk | | Email auth passing | SPF, DKIM, DMARC all pass | Protects sender reputation and delivery | Emails land in spam or get rejected | | No exposed secrets | Zero API keys or tokens in client bundle or repo | Prevents account takeover and abuse | Data leaks, billing fraud, outage | | Secure forms | Form input validated server-side with rate limits | Stops spam and injection attempts | Inbox flooding, malicious payloads | | Redirects cleanly set | www/non-www and trailing paths resolve once only | Avoids duplicate content and phishing confusion | Broken links, SEO loss, user distrust | | Production env vars only | No staging URLs or test keys in prod build | Prevents accidental data crossover | Leaks test data into live flow | | Monitoring active | Uptime alert fires within 5 minutes of failure | You need fast detection before users complain | Longer outages and support load | | Cache policy sane | Static assets cached; HTML not cached incorrectly | Improves speed without stale content bugs | Slow load times or outdated pages |

The Checks I Would Run First

1. DNS and canonical routing

Signal: The domain resolves to one production destination only. `www` and non-`www` should not split traffic across different hosts.

Tool or method: `dig`, browser checks, Cloudflare DNS dashboard, and a crawl of both variants. I also test direct origin access to make sure the app is not bypassing Cloudflare.

Fix path: Set one canonical host. Add 301 redirects from every alternate version to the preferred URL. If there are subdomains like `app.` or `api.`, make sure each has an explicit purpose and does not expose admin surfaces by accident.

2. TLS and mixed content

Signal: The site shows a valid certificate chain with no browser warnings. There should be no HTTP assets loaded on an HTTPS page.

Tool or method: Chrome DevTools Security tab, SSL Labs test, and a quick scan of network requests for `http://` assets.

Fix path: Force HTTPS at the edge. Replace any hardcoded asset URLs with relative or HTTPS URLs. If your builder injected third-party scripts over HTTP through old embeds, remove them before review.

3. Cloudflare edge protection

Signal: Cloudflare proxy is active with WAF basics turned on where appropriate. Rate limiting should exist for form submissions if the landing page accepts leads.

Tool or method: Cloudflare dashboard review plus a simple curl test to confirm headers indicate edge protection rather than direct origin exposure.

Fix path: Put the site behind Cloudflare orange-cloud proxy. Turn on DDoS protection and bot filtering where available. Lock down origin access so only Cloudflare can reach it.

4. Secrets exposure audit

Signal: There are no public secrets in source code, build artifacts, browser bundles, logs, or environment files committed by mistake.

Tool or method: Search the repo for patterns like `sk_`, `pk_live`, `AIza`, `.env`, private webhook URLs, and service credentials. Also inspect deployed JavaScript bundles because many founders miss secrets hidden there.

Fix path: Move secrets into server-side environment variables only. Rotate any key that was ever exposed publicly. If a secret reached Git history or a deployed bundle, assume it is compromised.

## Example only: keep secrets server-side
NEXT_PUBLIC_SITE_URL=https://example.com
STRIPE_SECRET_KEY=stored_in_host_env_not_repo
CLOUDFLARE_API_TOKEN=stored_in_host_env_not_repo

5. Email authentication setup

Signal: SPF passes for your sender domain; DKIM signs outgoing mail; DMARC policy exists at minimum in monitoring mode.

Tool or method: MXToolbox checks plus a real test email sent to Gmail and Outlook to inspect authentication results.

Fix path: Publish correct DNS records for your email provider. Start DMARC at `p=none` if you need visibility first, then tighten later once delivery is stable. For marketplace products that send invites or onboarding emails from day one, this is non-negotiable.

6. Form handling and abuse controls

Signal: Contact forms do not accept arbitrary payloads without validation. Spam volume stays low even under repeated submissions.

Tool or method: Submit normal inputs plus malformed payloads: long strings, script tags, header injection attempts, repeated posts from one IP.

Fix path: Validate on server side first. Add rate limits per IP and per session. Use honeypot fields or CAPTCHA only if needed; I prefer lightweight controls before adding friction that hurts conversion.

Red Flags That Need a Senior Engineer

1. Secrets already shipped in production

If an API key was embedded in frontend code or checked into GitHub history once already shown publicly by the app builder platform output logs), I would not treat this as a quick DIY fix anymore. You need rotation planning because leaked credentials often create silent billing damage before anyone notices.

2. The landing page talks directly to sensitive APIs from the browser

If customer data flows from client-side code straight into third-party services without server mediation, your attack surface is too wide for a founder-managed launch. This creates exposure around auth tokens,, CORS mistakes,,and data leakage through browser tooling.

3. You cannot explain who owns DNS,email,and hosting

When ownership is split across multiple tools with no clear admin access map,the next incident becomes guesswork instead of response.This usually means delayed recovery when something breaks during review day.

4. Staging looks like production

If test content,test keys,and real lead capture are mixed together,you are one bad deploy away from sending internal data to customers.I see this often with AI-built apps because preview environments get promoted too quickly without cleanup.

5.The site has already been flagged by reviewers,support,and spam filters

If you have had rejected submissions,bounced emails,browser warnings,and user reports about "unsafe" behavior,the problem is probably systemic.A senior engineer needs to trace root cause across DNS,deployment,email,and application logic rather than patching symptoms one by one.

DIY Fixes You Can Do Today

1.Clean up your public DNS records

Remove old A,CNAME,and TXT records you no longer use.Keep only what supports production,email,and verification.If you have duplicate records pointing to dead hosts,you are creating confusion for both reviewers and mail systems.

2.Verify every login-free public page uses HTTPS

Open the homepage in an incognito window.Check that typing `http://` always lands on `https://`.If it does not,you have an avoidable trust problem that can look sloppy during security review.

3.Run an exposed secret scan right now

Search your repo,and if possible your deployed bundle artifacts.For founders,this catches more problems than most manual reviews because builders often paste keys into config files without realizing they become public later.Rotate anything suspicious immediately.

4.Send yourself test email from the live domain

Use Gmail and Outlook accounts.Check whether the message lands in inbox,promotions,social,promotional tabs-or spam-and inspect authentication headers.If SPF,DKIM,and DMARC do not pass,you should fix mail before asking users to trust onboarding emails from your marketplace product.

5.Add basic uptime monitoring before launch day

Set up alerts using UptimeRobot,Pingdom,and similar tools so you know about failures fast.Even a simple landing page needs monitoring because downtime during review can delay approval by days,and each delay costs momentum plus support time.

Where Cyprian Takes Over

Here is how I map common failures to Launch Ready deliverables:

| Failure found in checklist | What I do in Launch Ready | | --- | --- | | DNS confusion or broken routing | Clean DNS setup,cannonical redirects,www/non-www resolution | | SSL warnings or mixed content errors | SSL enforcement,HSTS-friendly setup,and asset cleanup | | Origin exposed directly to traffic | Cloudflare proxy,DDoS protection,and origin lock-down | | Spammy contact form behavior | Production-safe form handling,routing,and basic abuse controls | | Missing SPF/DKIM/DMARC | Email authentication records configured correctly | | Secret leakage risk | Environment variable migration,secrets cleanup,handover notes | | No visibility after launch | Uptime monitoring plus alerting setup | | Unclear handoff process | Deployment checklist,end-state documentation,and owner notes |

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
• OWASP Top Ten: https://owasp.org/www-project-top-ten/
• Cloudflare Learning Center - DDoS Protection: https://www.cloudflare.com/learning/ddos/ddos-protection/

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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.*