Vercel Flags SDK with Next.js 16: Feature Flags, A/B Testing, and Rollout Patterns (2026)
Server-side feature flags in Next.js 16 without client bundles or flash-of-wrong-variant. Walk through install, Edge Config storage, precomputation for static routes, percentage rollouts, kill switches, and how the SDK compares to LaunchDarkly, Statsig, and GrowthBook.