Cursor Wrote Most of Your App: 10 Code Review Checks Before You Scale
More customers make hidden gaps more expensive
Your Cursor-built app has moved beyond a private project. Customers are signing up, returning, and relying on it to get work done. Whether you are a solo founder or act as your own Cursor developer, that traction marks a great moment to inspect the foundation under the hood.
AI coding tools let you move fast, but a feature working once in testing is only initial proof. It does not reveal what happens when an external service slows down, a customer clicks twice on checkout, an account requests the wrong database record, or a list expands from five items to 5,000.
This checklist helps you review Cursor generated code from the outside first. Each item separates what you can safely observe today from what requires repository access and a senior engineer's judgment. Always use test accounts and mock data for unusual behaviour. Never paste passwords, API keys, private code, or customer information into a public tool.
Your personal observations will help focus an AI written code review. However, external checks alone cannot confirm that your software is secure, reliable, or ready for sudden growth.
1. Check where passwords and API keys live
What you can check today: Look through your app settings, configuration files, and repository files for passwords or API keys written in plain text. A repository is where your app's code and change history are stored. Keep any finding private. Do not copy a secret into an AI chat, public scanning tool, or screenshot.
Why it matters: A credential committed into code may give unauthorized access to a paid service, database, or customer information. If a key appears in a current file, it may also exist in past commits.
What needs a senior engineer's review: Ask: "Are secrets stored safely? Do any appear in past code changes? Which exposed keys need replacing?" Removing a key from the latest file may still leave an earlier copy accessible in version history. For more on spotting vulnerabilities early, read about how AI code quality is an application security problem.
2. Check account boundaries
What you can check today: Create two test accounts. Add different data you own to each. Use the normal screens to view, edit, and download records. Note anywhere the accounts appear to overlap. Stop immediately if you encounter information that could belong to a real customer.
Why it matters: Signing in confirms who a person is. Your app must also limit them strictly to the records they are permitted to view or edit.
What needs a senior engineer's review: Ask: "Does the server confirm which account owns every requested record, including requests made outside the app's normal screens?" Checking screens alone cannot verify server authorization logic.
Possible credential exposure or access to another account's data needs prompt technical help. Do not experiment further with live customer records.
3. Check what happens when another service fails
What you can check today: If your app connects to another service, use a test account to see what happens when that service is unavailable or takes too long to respond. Use a safe test setting where one exists. Record the message you see and whether the action finished. Do not disrupt a live service to create a failure.
Why it matters: Customers need to know whether to wait, retry, or contact support. A vague message can lead them to repeat an action that already worked.
What needs a senior engineer's review: Ask: "What happens when this request times out or fails? Does the app explain the next step clearly? Could an automatic retry repeat the action?"
4. Check actions that must happen only once
What you can check today: In a test environment, double-click or refresh during an important action, such as a signup or booking. If your app takes payments, use your payment provider's test mode rather than a live charge. Check whether the result appears once or twice.
Why it matters: A slow response can make a customer click again. Depending on the feature, this may create duplicate records, messages, bookings, or charges.
What needs a senior engineer's review: Ask: "How does the code prevent duplicates? What happens when the first half of this action succeeds and the second half fails?" One clean test run cannot answer either question.
5. Check slow screens and growing lists
What you can check today: Open your busiest screen with a test account that has more records than a new user. Time roughly how long it takes to load. Then search, filter, or move through the list. Note which action slows down and how much test data you used.
Why it matters: A screen that feels quick with five records can become frustrating as a customer's history grows. Every app reaches that point at a different volume.
What needs a senior engineer's review: Ask: "Does this screen request far more data than it displays? Are the database queries and indexes suitable as data grows?" An index helps a database find records without scanning every single row.
6. Check limits on repeated or costly actions
What you can check today: List features that send emails, call paid services, or run AI features. For each one, note whether one person can trigger it repeatedly and where you can see its usage or cost. Use test accounts for any checks.
Why it matters: Repeated requests can increase cloud and AI costs or interrupt service, even when each request works as expected.
What needs a senior engineer's review: Ask: "Which actions need usage limits or access checks? How will we monitor their volume and cost?" The right limit depends on the feature and how customers use it.
For more on preparing an existing product for growth, see our guide on scalable startup infrastructure.
7. Check how a code change reaches the live app
What you can check today: Write down who can publish a change, where you try it before customers see it, and how you would return to the previous working version. Record any answer you cannot find. Do not test a return procedure on the live app without experienced help.
Why it matters: A small edit can affect a core customer action. A clear path back to a working version reduces the time customers spend blocked.
What needs a senior engineer's review: Ask: "Do the deployment settings support a safe return to the previous version? Can we test that procedure without disrupting customers?"
8. Check backups and restoration
What you can check today: Find the backup settings for services that store your app's data. Record what appears to be backed up and when the latest backup ran. Add any unclear setting to your review notes.
Why it matters: A backup only helps when it includes the required data and can actually be restored when an outage occurs.
What needs a senior engineer's review: Ask: "Which data is included? How far back can we recover? Can we test restoration somewhere safe?" A restoration test must never replace live customer data.
9. Check the customer journeys your business relies on
What you can check today: List the steps customers must complete to get value from your app. Depending on your product, that could include signing up, saving work, making a booking, receiving an email, or getting an AI-generated result. After a change, walk through those steps with test accounts and note anything that differs from your expectation.
Why it matters: A change in one feature can unintentionally break another. The journeys customers use most deserve repeatable quality checks.
What needs a senior engineer's review: Ask: "Which journeys should have automated testing? Are important business rules copied across several files?" Copied logic means a later change might update one place while missing another. Understanding these challenges starts with recognizing the verification gap when shipping AI code quickly.
10. Check how you learn that something failed
What you can check today: Find where you would see a failed request, customer-reported error, or alert. Imagine a customer says, "I saved it, but nothing happened." Write down what you could use to investigate and what you cannot see today.
Why it matters: When failures are hard to spot, customers may report them before you know they exist. Missing detail also makes the root cause harder to find.
What needs a senior engineer's review: Ask: "What monitoring and request tracking would help us find and explain this failure? How will we keep sensitive customer data out of error records?" Request tracking follows an action through the app so you can see exactly where it stopped. You can also explore how to run an AI audit for code quality to catch subtle operational gaps.
Keep your findings in one place
Check | What you can check today | What needs a senior review |
|---|---|---|
| Look for visible secrets in settings and files. | Secret storage, code history, and key replacement. |
| Compare two test accounts. | Server-side ownership checks. |
| Observe safe test failures. | Timeouts, retries, and clear failure handling. |
| Try repeated clicks in a test environment. | Duplicate prevention and partial failures. |
| Try screens with larger test lists. | Database queries and indexes. |
| List paid, email, and AI actions. | Usage limits, access checks, and cost monitoring. |
| Map the path from a change to the live app. | Safe return procedures. |
| Find backup settings and dates. | Recovery scope and restoration testing. |
| Retest key customer actions. | Automated testing and duplicated business rules. |
| Locate errors and alerts. | Monitoring and request tracking. |
Turn observations into a practical review
Start with anything that could expose customer data or paid-service credentials. Next, address actions that may execute twice, especially payments, bookings, emails, or AI requests. After that, work through slow screens, recovery gaps, and failures you cannot easily observe today.
Bring a senior engineer clear notes: what you tried, what happened, and what remains unclear. That gives them a focused starting point and gives you an honest view of the risks worth addressing first.
Smicolon's Solo Founder Plan gives you ongoing senior engineering guidance while you keep building. It costs €1,000 per month for 40 hours (€25 per hour) with a 3-month minimum. You receive a weekly 1-hour 1:1 with a senior engineer, plus a thorough check on what the AI wrote. You remain the builder.
Smicolon starts with the app you already have. No rebuild is proposed, and no particular outcome is guaranteed. The plan ends at the end date or when the hours are used up, whichever comes first.
Book a discovery call to discuss your checklist findings and decide what deserves attention first.