Security · Definition
What pen testing is, how it differs from a scan or review, what it covers for a web app, when to commission one and its limits.
Last updated: October 2026. Written by Athar Ahmad, Certified Bubble.io Developer and Tech Architect, Simple Automation Solutions.
Quick answer
Penetration testing is an authorised, simulated attack by security specialists to find weaknesses before real attackers do. It differs from an automated vulnerability scan, which finds known issues broadly, and from a design-focused security review. For web apps it covers authentication, access control, input handling, business logic, APIs, file handling and configuration. Consider one before or soon after launch if the app holds sensitive data or customers ask for evidence, after fixing the basics. It is a snapshot, not a guarantee.
Key takeaways
- Pen test = authorised simulated attack by specialists; scan = automated check for known issues.
- Covers authentication, access control, logic flaws, APIs, files and configuration.
- Fix the basics and test access control yourself first.
- On a platform like Bubble, scope is your app’s configuration and logic; check the platform’s testing rules.
- A pen test is a snapshot, not proof of perfect security.
In this guide
- What is penetration testing?
- Pen test vs vulnerability scan vs security review
- What does a pen test cover for a web app?
- Types of test
- When does a small app need one?
- What can you do before paying for a pen test?
- What about apps on a platform such as Bubble.io?
- How do you choose a tester and use the results?
- What are the limits?
- Frequently asked questions
What is penetration testing?
Penetration testing, often called pen testing, is an authorised, simulated attack on a system carried out by security specialists to find weaknesses before real attackers do. Testers try to get around the system’s defences the way an attacker would, then report what they found, how serious it is and how to fix it.
Pen test vs vulnerability scan vs security review
| Vulnerability scan | Penetration test | Security review or audit | |
|---|---|---|---|
| How it works | Automated tool checks for known weaknesses | Skilled human testers actively try to exploit weaknesses | Expert examines design, configuration and practices against a checklist |
| Depth | Broad, shallow | Narrower, deep | Broad, design-focused |
| Finds | Known issues, misconfigurations | Real-world attack paths, logic flaws, chained weaknesses | Missing controls, weak design, policy gaps |
| Cost and effort | Low | Higher | Moderate |
| Typical frequency | Regularly | Before launch and periodically | Before launch, after major change |
What does a pen test cover for a web app?
- Authentication and session handling.
- Access control: can one user reach another’s data?
- Input handling and common web vulnerabilities.
- Business logic flaws, such as skipping a step or abusing a workflow.
- APIs and integrations.
- File upload and download handling.
- Data exposure through the interface or network responses.
- Configuration and secrets handling.
Types of test
| Type | What testers know | Use |
|---|---|---|
| Black box | Nothing beyond what a public attacker would know | Realistic outsider view |
| Grey box | Some knowledge, such as user accounts and documentation | Efficient, common for web apps |
| White box | Full information, such as design and configuration | Deepest coverage |
When does a small app need one?
| Situation | Suggestion |
|---|---|
| An early prototype with no real data | Not yet. Do your own testing |
| A portal or SaaS holding client or sensitive data | Consider a test before or soon after launch |
| A customer or regulator requires evidence | Commission one |
| After a major redesign or new integration | Re-test the affected areas |
| Handling payments, health or financial data | Strongly consider, plus regular reviews |
What can you do before paying for a pen test?
- Design roles and privacy rules properly. See our security guide and database design mistakes.
- Test access control yourself with at least two accounts per role.
- Keep keys private and review integrations.
- Use multi-factor authentication for staff and admins.
- Review logs and set alerts.
- Fix what you find, then test again.
A pen test is far more valuable when the basics are already sound. Otherwise it simply tells you what a basic review would have.
What about apps on a platform such as Bubble.io?
The platform provider is responsible for its own infrastructure, so testing normally focuses on your app’s configuration and logic: privacy rules, workflows, data exposure, API settings and integrations. Check the platform’s rules on security testing before you or a tester begin, since some platforms require notice or permission, and agree scope in writing. Findings about the platform itself should go to the provider.
How do you choose a tester and use the results?
- Ask for relevant experience, methodology, sample report format and references.
- Agree scope, timing, permitted techniques and data handling in writing.
- Use test data, not live customer data, where possible.
- Expect a report with severity ratings and fix guidance.
- Fix high-severity items promptly, then ask for a retest.
- Keep the report and remediation record, which customers may ask to see.
What are the limits?
- A pen test is a snapshot. New changes can introduce new weaknesses.
- It covers the agreed scope only.
- It does not replace secure design, monitoring or good practices.
- No test proves a system is perfectly secure.
Simple Automation Solutions designs access control, keys and logging into builds, tests with multiple accounts before launch and can work with your chosen tester to fix findings. Builds start at $3,500; support and fixes are from $35 per hour, with no retainers or minimums. We do not carry out independent penetration tests ourselves.
Frequently asked questions
What is penetration testing?
An authorised, simulated attack by security specialists to find weaknesses in a system before real attackers do, followed by a report of findings and fixes.
What is the difference between a pen test and a vulnerability scan?
A scan is automated and finds known issues broadly. A pen test uses skilled testers to actively exploit weaknesses and finds deeper problems such as logic flaws.
Does my small app need a penetration test?
If it holds sensitive or client data, consider one before or soon after launch, especially if customers or regulators ask for evidence.
How often should I test?
Before launch, after major changes and periodically, with simple internal checks in between.
Can I pen test an app built on a no-code platform?
Yes, focusing on your app’s configuration and logic. Check the platform’s rules on security testing first and agree scope in writing.
Want your app’s access control and security reviewed?
Email us what the app holds and who uses it. We will review the basics and tell you what to fix before any formal test.
Athar Ahmad, Certified Bubble.io Developer and Tech Architect, Simple Automation Solutions
About Simple Automation Solutions (SA Solutions)
Simple Automation Solutions is a Bubble.io development studio led by Athar Ahmad, a Certified Bubble.io Developer and Tech Architect. It builds web and mobile apps, client portals and SaaS products for founder-led businesses such as law firms, accounting firms, boutique agencies and consultants. Services include a free 30-minute Idea Audit, a $345 Discovery Sprint (a Product Requirements Document delivered within 24 hours, credited toward the build) and builds starting at $3,500. Website: sasolutionspk.com.
