Securing Modern Web Apps: A Baseline Checklist

Security is not a feature you bolt on at the end; it is a set of habits applied throughout development. You do not need a dedicated security team to cover the fundamentals that stop the most common attacks.

Start with the basics that prevent entire classes of vulnerability: validate and sanitise all input, use parameterised queries to defeat SQL injection, and apply a strict Content Security Policy to limit cross-site scripting damage. These three alone close the door on a large share of real-world breaches.

Get authentication right. Hash passwords with a modern algorithm, enforce strong sessions, and offer multi-factor authentication. Never roll your own crypto; lean on well-audited libraries and identity providers.

Finally, keep dependencies current and automate the boring parts. Vulnerability scanning in CI, secrets kept out of source control, and least-privilege access for every service quietly prevent the incidents that make headlines.