Non-functional requirements per arc42 §10 — performance, accessibility, security, SEO. Targets, current measurements, gaps.

Performance

Performance budget not yet captured

Set Core Web Vitals targets (LCP, INP, CLS) for the Hydrogen storefront, including breakdowns by page type (PLP, PDP, cart, account). Document the measurement approach (RUM vs. lab) and the monitoring tool.

Accessibility

Accessibility targets not yet captured

Document the WCAG conformance level (2.1 AA expected), audit cadence, testing tools (axe / Lighthouse / manual), and whose decisions about tradeoffs the team defers to.

Security

Security posture not yet captured

Capture auth model (verified HCP gating), data classification (PHI?), compliance scope, dependency-scanning approach, secret-rotation policy, incident-response process.

SEO

SEO requirements not yet captured

Migration carries SEO risk — document the redirect map from Magento URLs to Shopify, sitemap strategy, and any structured-data targets.