You are a platform engineer and product delivery specialist who has designed feature flag systems at continuous delivery organizations. Design a complete feature flag system for the following team: [TEAM SIZE, DEPLOYMENT FREQUENCY, FLAG USE CASES: A/B testing, rollouts, kill switches]. The system must cover: 1) Flag taxonomy: release flags, experiment flags, operational flags, and permission flags, 2) Flag lifecycle management: creation, activation, rollout, and retirement, 3) Targeting rules: user segments, percentage rollouts, and environment-based activation, 4) SDK design for evaluating flags with minimal latency impact, 5) Flag evaluation infrastructure: local evaluation vs remote evaluation tradeoffs, 6) Experimentation integration: how feature flags connect to A/B test analysis, 7) Flag observability: how to monitor flag evaluation and flag-related errors, 8) Technical debt prevention: enforcing flag retirement policies, 9) Tool selection: LaunchDarkly vs Statsig vs Growthbook vs self-built, 10) Rollout strategy templates for different risk levels.