Launch Ready cyber security Checklist for mobile app: Ready for production traffic in marketplace products?.

Launch Ready cyber security Checklist for mobile app: Ready for production traffic in marketplace products?

"Ready for production traffic" means more than "the app opens on my phone." For a marketplace mobile app, I want to see that a stranger can install it, sign up, browse listings, transact, receive emails, and recover from errors without exposing customer data or breaking trust.

If I were self-assessing, I would call the app ready only if these are true:

• No exposed secrets in the repo, build logs, or client bundle.
• Auth is enforced on every private API route.
• Email deliverability is set up with SPF, DKIM, and DMARC passing.
• Domain, SSL, redirects, and subdomains are correct.
• Cloudflare or equivalent edge protection is live.
• Uptime monitoring alerts me before customers do.
• p95 API latency stays under 500ms for core flows.
• No critical auth bypasses, IDORs, or broken role checks.
• Production deployment is repeatable and documented.
• I can hand the app to support without guessing how it works.

For marketplace products, the risk is not just downtime. It is fake listings, account takeover, payout fraud, broken onboarding, support overload, and ad spend wasted on traffic that lands on a half-secure product.

Quick Scorecard

| Check | Pass criteria | Why it matters | What breaks if it fails | |---|---|---|---| | Domain and DNS | Root domain and app subdomain resolve correctly; redirects are intentional | Users must land on the right app and trust the URL | Broken login links, SEO loss, phishing risk | | SSL/TLS | Valid certs on all public endpoints; no mixed content | Protects sessions and customer data | Browser warnings, blocked requests | | Auth coverage | Every private endpoint requires auth; no public write routes | Stops account takeover and data leaks | Exposed orders, messages, profiles | | Secrets handling | Zero secrets in repo or client bundle; env vars only on server | Prevents key theft and API abuse | Billing fraud, leaked tokens | | Email setup | SPF/DKIM/DMARC all pass | Stops emails landing in spam or spoofing attacks | Failed verification emails, phishing risk | | Edge protection | Cloudflare rate limits and DDoS protection enabled | Reduces bot abuse and traffic spikes | Signup floods, scraping, outage | | Logging and monitoring | Errors logged without secrets; uptime alerts active | Lets you detect incidents fast | Silent failures and long outages | | API performance | p95 core API under 500ms | Keeps onboarding and browsing usable at scale | Slow conversion and abandoned sessions | | Storage access control | Private files are not public by default; signed URLs used where needed | Prevents data exposure through object storage | Leaked images, documents, attachments | | Release process | Production deploy is documented with rollback path | Limits release mistakes under pressure | Broken launch with no recovery plan |

The Checks I Would Run First

1. Auth bypass check

• Signal: I can hit a private endpoint without a valid session or token.
• Tool or method: Manual testing with Postman or curl plus route review in the backend code.
• Fix path: Add middleware or guards at the route layer first. Then verify server-side authorization on every object fetch so user A cannot read user B's listing or order.

2. Secret exposure check

• Signal: API keys appear in the mobile bundle, repo history, CI logs, or `.env` files committed by mistake.
• Tool or method: Search the repo for `sk_`, `pk_`, `secret`, `token`, `PRIVATE_KEY`, then scan build artifacts.
• Fix path: Move secrets to server-side env vars only. Rotate anything already exposed. If a secret shipped in a client build once, assume it is compromised.

3. Email deliverability check

• Signal: Verification emails go to spam or fail authentication tests.
• Tool or method: Use MXToolbox or Google Postmaster Tools plus a test send to Gmail and Outlook.
• Fix path: Set SPF to authorize your sender only once. Add DKIM signing. Publish DMARC with reporting enabled so spoofing attempts are visible.

4. Edge protection check

• Signal: Repeated signup attempts succeed too easily or one IP can hammer endpoints without delay.
• Tool or method: Review Cloudflare firewall events and run a small rate-limit test from one client IP.
• Fix path: Turn on WAF rules for login/signup/reset flows. Add rate limits per IP and per account identifier. Block obvious bot patterns before they hit origin.

5. Storage access check

• Signal: Uploaded files load from public URLs without permission checks.
• Tool or method: Open file URLs in an incognito window after logging out. Try guessing object paths if they look predictable.
• Fix path: Move sensitive assets behind signed URLs or authenticated fetches. Make private buckets private by default.

6. Monitoring check

• Signal: A crash can happen for hours before anyone notices.
• Tool or method: Inspect uptime monitors, error tracking dashboards, webhook alerts, and escalation routing.
• Fix path: Add uptime checks for homepage, auth endpoint, and checkout flow. Alert to email plus Slack or SMS. Track 5xx spikes and failed jobs separately.

SPF=pass
DKIM=pass
DMARC=pass

That tiny line matters because if any of those fail consistently, your marketplace looks less trustworthy to inbox providers and users alike.

Red Flags That Need a Senior Engineer

1. You have multiple auth systems stitched together

• Example: Firebase auth on mobile plus custom JWTs plus an admin portal with separate roles.
• Why I would step in: This usually creates permission drift and hidden bypasses.

2. The backend trusts client-sent IDs

• Example: The app sends `userId`, `sellerId`, or `listingOwnerId` from the device and the server accepts it.
• Why I would step in: That is how IDOR bugs happen in marketplaces.

3. Secrets were already committed once

• Example: Stripe keys, SendGrid keys, Supabase service roles, Maps keys in Git history.
• Why I would step in: Rotation is not optional after exposure.

4. You are launching with bots already attacking signup

• Example: Fake accounts appear during beta testing or scraping starts before launch.
• Why I would step in: Marketplace abuse scales fast and breaks trust early.

5. Nobody knows how rollback works

• Example: The team says "we will just redeploy" but there is no tagged release or backup plan.
• Why I would step in: Production traffic punishes vague deployment habits immediately.

DIY Fixes You Can Do Today

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

• Assume anything shared outside your server could leak later.
• Start with payment keys, email provider keys, database credentials, cloud storage credentials.

2. Turn on MFA everywhere

• Email provider first, then cloud hosting, DNS registrar, GitHub/GitLab/Figma/Notion admin accounts.
• Marketplace apps often get breached through weak admin access before code is even touched.

3. Audit your public URLs

• Check root domain redirect logic,

app subdomain, password reset links, invite links, email templates, deep links from push notifications.

4. Test signup like an attacker

• Create 10 accounts from one device if possible.
• Try duplicate emails,

disposable emails, weak passwords, repeated reset requests, rapid form submission, expired links.

5. Write down your launch owners

• One person owns DNS,

one owns deployment, one owns support escalation, one owns incident response.

• If nobody owns each area clearly enough to answer at 2 am UTC/ET/PT time zones matter less than ownership.

Where Cyprian Takes Over

Here is how checklist failures map to the service:

| Failure found | Deliverable I handle | |---|---| | DNS misroutes or bad redirects | Domain setup cleanup across root domain, www/app subdomains, canonical redirects | | SSL warnings or mixed content | TLS validation across public endpoints and asset loading paths | | Weak edge protection | Cloudflare setup for caching rules, DDoS protection, firewall rules | | Email failures | SPF/DKIM/DMARC configuration and sender verification fixes | | Secret leakage risk | Environment variable cleanup plus secret handling review before deploy | | Broken deployment flow | Production deployment with handover checklist and rollback notes | | No uptime visibility | Monitoring setup for critical endpoints plus alert routing | | Public/private data confusion | Access-control review for obvious exposure paths before launch |

My recommended delivery order is simple:

1. Hour 0 to 8: audit DNS, SSL readiness, email auth status, secrets exposure points. 2. Hour 8 to 20: fix edge settings in Cloudflare plus redirect structure and caching rules. 3. Hour 20 to 32: deploy production build safely with environment variables separated from client code. 4. Hour 32 to 40: add monitoring on homepage/login/core API flows and confirm alert delivery. 5. Hour 40 to 48: run handover checks so you know what was changed, what still needs attention, and what support should watch after launch.

For marketplace apps specifically:

• I prioritize login,

listing creation, search/browse, checkout/payout paths, and admin controls first.

• I do not waste launch time polishing non-critical UI while auth gaps remain open.
• If something cannot be made safe inside scope,

I will say so directly rather than pretend it is ready.

Delivery Map

References

• https://roadmap.sh/api-security-best-practices
• https://roadmap.sh/cyber-security
• https://roadmap.sh/code-review-best-practices
• https://roadmap.sh/backend-performance-best-practices
• https://developers.cloudflare.com/fundamentals/ssl/
• https://support.google.com/a/answer/33786?hl=en
• https://www.rfc-editor.org/rfc/rfc7489

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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.*