Launch Ready API security Checklist for founder landing page: Ready for handover to a small team in mobile-first apps?.

What "ready" means for a founder landing page with mobile-first apps

For this product, "ready" means a small team can take over without breaking launch, leaking secrets, or losing traffic from bad DNS and email setup. It also means the landing page can support paid acquisition on mobile without slow loads, broken redirects, or API endpoints that fail under real user traffic.

If I audit this properly, I want to see all of the following before handover:

• Domain points to the correct production app.
• SSL is valid on every public subdomain.
• Email authentication passes SPF, DKIM, and DMARC.
• Secrets are not in the repo, build logs, or frontend bundle.
• API auth is enforced on every protected route.
• Rate limits exist on public endpoints.
• Monitoring alerts someone within 5 minutes if the site goes down.
• Mobile LCP is under 2.5s on a mid-range phone over 4G.
• No critical auth bypasses, no exposed admin routes, and no open CORS policy.

For a founder, "ready" is not "the site loads on my laptop." It is "a small team can inherit this, ship updates safely, and not spend the next month cleaning up preventable incidents."

Quick Scorecard

| Check | Pass criteria | Why it matters | What breaks if it fails | |---|---|---|---| | Domain and DNS | Root domain and www resolve correctly in under 60 seconds TTL | Prevents launch confusion and stale routing | Users hit old pages or dead hosts | | SSL everywhere | HTTPS valid on root and subdomains with no mixed content | Protects logins and trust | Browser warnings, blocked assets | | Redirects | One canonical path for www/non-www and trailing slash rules | Keeps SEO and analytics clean | Duplicate pages and broken links | | Email auth | SPF, DKIM, DMARC all pass | Stops spoofing and deliverability issues | Emails go to spam or get rejected | | Secrets handling | Zero secrets in frontend code or repo history | Prevents account takeover and data leaks | Keys get stolen from bundle or Git | | API auth | No protected endpoint accessible without valid session/token | Stops unauthorized access | Data exposure and account abuse | | Rate limiting | Public auth and form endpoints limited per IP/user/device | Protects against brute force and spam | Cost spikes and downtime | | CORS policy | Allowlist only known origins; no wildcard with credentials | Limits cross-site abuse | Token theft or unauthorized browser calls | | Monitoring | Uptime + error alerts active with a 5 minute response path | Reduces silent failures during launch ads spend | You burn traffic while broken | | Mobile performance | LCP under 2.5s, CLS under 0.1 on key pages | Mobile-first users convert faster when load is fast | Lower conversion and higher bounce |

The Checks I Would Run First

1. DNS and canonical routing

• Signal: root domain, www, app subdomain, and any marketing subdomain all resolve to the intended environment.
• Tool or method: `dig`, browser checks, Cloudflare dashboard review.
• Fix path: set one canonical host, add 301 redirects for everything else, lower TTL during launch windows.

2. SSL and mixed content

• Signal: padlock is valid on every public URL; no images, scripts, or fonts load over HTTP.
• Tool or method: browser devtools console, SSL Labs test.
• Fix path: force HTTPS at Cloudflare or origin, replace hardcoded `http://` assets, renew certificates before expiry.

3. Secrets exposure check

• Signal: no API keys in frontend bundles, Git history, build logs, or shared docs.
• Tool or method: repo scan with `git grep`, secret scanning tool, view source of deployed app.
• Fix path: rotate exposed keys immediately, move secrets to environment variables or vault-backed config.

4. Auth and authorization review

• Signal: every protected endpoint rejects unauthenticated requests; users cannot access another user's data by changing IDs.
• Tool or method: Postman/Insomnia manual tests plus direct URL tampering.
• Fix path: enforce server-side auth checks on each route; do not trust client-side role flags.

5. CORS and public API exposure

• Signal: only approved origins can call browser-facing APIs; credentials are never allowed with wildcard origins.
• Tool or method: inspect response headers from preflight requests.
• Fix path: replace `*` with exact origins and separate public read-only endpoints from private ones.

6. Monitoring and alerting

• Signal: uptime checks exist for homepage, API health endpoint, checkout/contact flow if present; alerts reach email/Slack/SMS quickly.
• Tool or method: uptime monitor plus forced outage test.
• Fix path: create a simple `/health` endpoint for infra checks; wire alerts to at least two people.

A simple config rule I like for launch safety is this:

SPF: v=spf1 include:_spf.google.com include:_spf.mailgun.org ~all
DMARC: v=DMARC1; p=quarantine; rua=mailto:dmarc@yourdomain.com

That is not the full setup by itself. It is just the minimum shape I expect before a founder sends important mail from a new domain.

Red Flags That Need a Senior Engineer

1. The app uses secret keys in client-side code

• If an API key is visible in the browser bundle, assume it is already compromised.

2. There is no clear auth boundary

• If the same endpoint serves public content and private user data without strict checks, you are one bug away from exposure.

3. The team cannot explain who owns DNS and email

• Launch breaks often happen because nobody knows where records live or who can change them.

4. The site depends on one person remembering manual steps

• If deployment requires "just run these commands" without docs or automation, handover will fail.

5. You are spending ad money before monitoring exists

• Paid traffic into an unmonitored landing page is expensive guesswork. A one-hour outage can waste far more than this service costs.

DIY Fixes You Can Do Today

1. Inventory every domain and subdomain

• Write down root domain, www, app., api., mail., staging., and any old launch domains.
• Confirm which ones should redirect versus serve content.

2. Rotate any exposed keys now

• If you have ever pasted secrets into chat tools, screenshots, issue trackers, or frontend env files that shipped publicly, rotate them first.

3. Turn on Cloudflare proxying where appropriate

• Use Cloudflare for DNS control, SSL termination where needed, caching static assets if safe to cache,

DDoS protection for public pages.

4. Set up basic email authentication

• Add SPF first.
• Add DKIM through your provider.
• Add DMARC with quarantine before moving to reject once you confirm deliverability.

5. Write down your handover map

• List registrar login, DNS host login, hosting provider login,

email provider login, analytics access, monitoring access, repository access, deployment pipeline access.

Where Cyprian Takes Over

This service is built for the exact failures that turn a "working prototype" into a messy launch week.

• DNS cleanup for root domains and subdomains
• Canonical redirects for www/non-www
• Cloudflare setup for SSL caching where safe DDoS protection
• SPF DKIM DMARC configuration
• Production deployment verification
• Environment variables review
• Secrets cleanup guidance
• Uptime monitoring setup
• Handover checklist for a small team

Here is how I would map failure to action:

| Failure found in audit | Service deliverable I use | |---|---| | Wrong domain points live site somewhere else | DNS correction + redirect plan | | SSL errors or mixed content warnings | Cloudflare SSL + asset cleanup | | Emails land in spam/rejected state | SPF/DKIM/DMARC setup | | Keys exposed in code/history/logs | Secret rotation + env var migration | | Public API has weak auth/rate limits/CORS issues around landing page forms or mobile app hooks | Production hardening review before handover | | No alerting after deploys fail silently | Uptime monitoring + alert routing | | Team lacks ownership docs for launch ops | Handover checklist with access map |

My recommendation is simple: if you already have traffic planned within 7 days and any of those items are unclear, buy the service instead of trying to patch it yourself at midnight. lost signups, and ad spend wasted on broken pages.

References

• Roadmap.sh Code Review Best Practices: https://roadmap.sh/code-review-best-practices
• Roadmap.sh API Security Best Practices: https://roadmap.sh/api-security-best-practices
• Roadmap.sh Cyber Security: https://roadmap.sh/cyber-security
• Cloudflare SSL/TLS documentation: https://developers.cloudflare.com/ssl/
• Google Search Central on redirects: https://developers.google.com/search/docs/crawling-indexing/redirects

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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.*