Feature Flag Service
Studies in this cluster, in series order. Each one keeps its own URL.
Low-level design
OOP and SOLID class design for machine-coding LLD: interfaces, invariants, in-memory state, and concurrency you can implement and test.
Feature Flag Service
3 studies- 1.Feature Flag Service LLD - Targeting, Sticky Buckets & Kill SwitchesProvisional machine-coding LLD for an in-memory flag service: kill switch, disabled, segment gate, then a sticky SHA-256 percentage.
- 2.Feature Flag Service - Sticky Bucket + Kill Switch Solution & TestsRunnable FlagStore with upsert, sticky SHA-256 bucketing, segment gates, kill-switch precedence, and a concurrent upsert/evaluate test.
- 3.Feature Flag Service - Evaluation Order & ConcurrencyWhy the kill switch short-circuits before the percentage, why get copies the flag, and how this round connects to progressive delivery.