Advanced⏱ 9 min read
Non-Functional Testing
sign in to trackNon-functional testing evaluates how a system performs under certain conditions, rather than what it does. This includes performance, security, usability, reliability, scalability, and maintainability — the 'ilities' that determine real-world quality.
◈Key Points
- Performance testing subtypes: Load (normal load), Stress (beyond limits), Soak (sustained load), Spike (sudden surge).
- Security testing: OWASP Top 10 is the industry standard checklist for web application vulnerabilities.
- Usability testing involves real users performing tasks — no amount of internal testing replaces it.
- Accessibility testing (WCAG compliance) is increasingly a legal requirement, not just a nice-to-have.
- Non-functional requirements are often underdefined — extract and document them explicitly early.
⚡ Expert Pro Tip
Treat non-functional requirements as first-class acceptance criteria in every sprint, not as a phase you do before release. Performance bugs are the hardest to fix late in development.