Module 20 · 1 chapters

Experimentation & Feature Flags

Feature flags decouple deploy from release — staff engineers design systems with sticky assignment, metric guardrails, holdout groups, and flag lifecycle management.

This module covers flag SDK bootstrap, ring deployments, auto-rollback on regression, holdouts for portfolio measurement, flag debt lint rules, and kill switches with CDN fallback.

Pairs with Frontend Reliability (Module 19) for guardrails and kill switch patterns.

Staff track module — complete Staff Frontend System Design (Module 16) first.

Chapters in this module

  1. Experimentation & Feature FlagsFeature flag architecture, sticky assignment, ring rollouts, metric guardrails, holdouts, flag debt lifecycle, and emergency kill switches.
Start with Experimentation & Feature Flags