How to Get Started with Secure Code Review (and Actually Become Good at It)

I keep getting asked the same questions by developers and security engineers:

“How do I learn secure code review?” “How do people get so good at finding vulnerabilities in code?” “What should I practice for AppSec interviews?”

And after seeing this play out again and again, I’ve come to a pretty strong conclusion:

Most people aren’t bad at code review; they’re just training the wrong skill.

The Myth: “If I Read Enough, I’ll Be Good at Code Review”

Most learning paths for AppSec look roughly like this:

• Read OWASP Top 10
• Watch conference talks
• Read blog posts explaining vulnerabilities
• Maybe do a few CTFs

This builds awareness, but awareness is not the same as review skill.

You can know what SQL injection is and still miss it in a real codebase. You can understand broken access control conceptually and still overlook it in business logic.

Secure code review isn’t about recalling definitions. It’s about judgment under ambiguity.

Why Secure Code Review Feels So Uncomfortable

Code review is uncomfortable because nothing is obviously broken.

• There’s no exploit running.
• There’s no scanner screaming.
• There’s no red “FAIL” indicator.

Instead, you’re staring at code that mostly works and asking:

What assumptions are being made here? Who controls this data? What happens in edge cases?

That uncertainty is exactly what makes AppSec interviews hard, and exactly what most people never practice.

Experienced reviewers don’t “read better.” They recognize patterns faster. And pattern recognition only comes from exposure.

Reading Is Necessary but It Will Never Be Sufficient

Let’s be clear: foundational resources matter.

1. OWASP Top 10
2. OWASP Cheat Sheets
3. Well-written security blogs and talks

These give you the vocabulary and mental models you need. But they don’t train your eyes.

Secure code review is deeply contextual:

• Language quirks
• Framework behaviour
• Data flow across layers
• Business logic assumptions

You don’t learn that by reading alone. You learn it by reviewing bad code that looks good.

What Actually Improves Secure Code Review Skill

In my experience, people meaningfully improve when they do three things consistently.

1. Review Code That Looks Real

Toy examples don’t help much.

You need code that:

• Compiles
• Passes tests
• Looks reasonable at first glance
• Still contains security flaws

This is how your brain learns to slow down and ask better questions.

2. Force Yourself to Explain the Risk

Finding an issue silently isn’t enough.

If you can’t explain:

• why it’s a vulnerability
• how it could be exploited
• what a safe fix looks like

…then you probably won’t perform well in interviews or real reviews. Strong AppSec engineers are strong communicators.

3. Practice Fixing, Not Just Finding

Fixing vulnerabilities forces you to think about tradeoffs.

• Is this fix safe everywhere?
• Does it introduce new risks?
• Does it fail closed?

This is where real intuition is built.

Why AppSec Interviews Expose This Gap So Quickly

Most AppSec interviews don’t care how many vulnerabilities you can name. They care about how you think when shown unfamiliar code.

You’re asked:

• “What would you review first?”
• “What concerns you here?”
• “How would you fix this?”

Candidates who struggle usually know security. They just haven’t reviewed enough real-world vulnerable code.

Resources That Are Actually Worth Your Time

There are good resources out there — but they serve different purposes.

For fundamentals:

• OWASP Top 10 (https://owasp.org/www-project-top-ten/)
• OWASP Cheat Sheets (https://cheatsheetseries.owasp.org/index.html)

For secure coding practice:

• Code Review Lab (https://www.codereviewlab.com/)
• OWASP VulnCodeLab (https://nest.owasp.org/projects/vulncodelab)
• Secure Code Warrior (https://www.securecodewarrior.com/)

The key is balance. No single resource is enough on its own.

The Advice I Give Everyone

If your goal is to:

• Pass AppSec interviews
• Get better at reviewing pull requests
• Transition from development into security
• Or stop feeling unsure when reviewing code

Then stop asking:

“What should I read next?”

And start asking:

“What code can I review next?”

That shift changes everything.

Final Thought

Secure code review is not a checklist. It’s not a tool! It’s not memorization!

It’s a judgment skill built through exposure, repetition, and reflection.

The sooner you practice it the way it’s actually used, the faster it stops feeling mysterious.