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Web Security Best Practices Every Developer Should Follow

Security
Web Security Best Practices Every Developer Should Follow

Security breaches make headlines every week, and the uncomfortable truth is that most of them are preventable. At TCCB Solutions, we've audited enough codebases to know that the same handful of mistakes show up again and again. The good news? A few solid habits go a long way toward keeping your applications and your users safe.

Here are the web security practices we consider non-negotiable for every project we touch.

1. Never Trust User Input

This is the golden rule of web security. Every piece of data that comes from a user — form fields, URL parameters, cookies, headers — should be treated as potentially malicious until proven otherwise.

The most dangerous mistake we see is building SQL queries with string concatenation:

// DANGEROUS — never do this
const query = "SELECT * FROM users WHERE email = '" + userEmail + "'";

An attacker can inject ' OR 1=1 -- into that field and dump your entire users table. Instead, always use parameterized queries:

// Safe — parameterized query
const query = "SELECT * FROM users WHERE email = $1";
const result = await db.query(query, [userEmail]);

This applies to every database library and every language. If you're writing raw SQL, use placeholders. If you're using an ORM, let it handle escaping — don't bypass it.

2. Sanitize Output to Prevent XSS

Cross-Site Scripting (XSS) happens when an attacker injects JavaScript into your page through stored or reflected user data. If you display a user's name on a profile page and they've set their name to <script>steal(document.cookie)</script>, you have a problem.

The fix is straightforward: escape all dynamic content before rendering it in HTML. Most modern frameworks do this by default — React escapes JSX expressions, Laravel's Blade escapes with {{ }}, and Django auto-escapes templates. The danger comes when you deliberately bypass it with things like dangerouslySetInnerHTML or {!! !!} in Blade. Only do this when you've sanitized the content with a library like DOMPurify first.

3. Use HTTPS Everywhere

There's no excuse to serve anything over plain HTTP in 2026. Free certificates from Let's Encrypt take minutes to set up, and most hosting platforms handle TLS automatically. Beyond encrypting data in transit, HTTPS enables security headers and is required for features like service workers and secure cookies.

While you're at it, set the Strict-Transport-Security header to tell browsers to always use HTTPS:

Strict-Transport-Security: max-age=31536000; includeSubDomains

4. Hash Passwords Properly

We still occasionally find applications storing passwords in plain text or using fast hashing algorithms like MD5 or SHA-256. These are not designed for passwords and can be cracked at billions of attempts per second.

Use bcrypt, scrypt, or Argon2 — algorithms specifically built to be slow and memory-intensive:

const bcrypt = require('bcrypt');

// Hashing a password
const hash = await bcrypt.hash(password, 12);

// Verifying a password
const match = await bcrypt.compare(password, storedHash);

The cost factor (12 in this example) makes each attempt deliberately expensive, which is exactly what you want when defending against brute force attacks.

5. Implement Proper Authentication and Session Management

A few rules we follow on every project:

6. Keep Dependencies Updated

Your application is only as secure as its weakest dependency. Run npm audit, composer audit, or your language's equivalent regularly. Subscribe to security advisories for the frameworks and libraries you depend on. A known vulnerability in an outdated package is one of the easiest attack vectors there is.

7. Follow the Principle of Least Privilege

Your database user shouldn't have DROP TABLE permissions if the application only needs to read and write rows. Your API keys shouldn't have admin access if the integration only needs read access. Every credential, service account, and user role should have the minimum permissions required to do its job — nothing more.

Security Is an Ongoing Practice

There's no single checklist that makes an application permanently secure. Threats evolve, dependencies age, and new features introduce new attack surfaces. The practices above aren't advanced techniques — they're the baseline. Building them into your workflow from day one is far cheaper than dealing with a breach after the fact.

If you're unsure about the security posture of your web application, or you're planning a new build and want to get it right from the start, reach out to us. We'd be happy to help you build something solid.