System Design
Advanced

Design a Feature Flag Platform

Serve low-latency configuration globally with targeting, auditability, and safe rollouts.

40 min
3 sections
feature-flags
configuration
rollouts
1
2
3

01. Optimize reads aggressively

Section 1 of 3

Flag evaluation happens on critical request paths. SDKs should evaluate locally from cached configuration, while the control plane handles authoring, validation, audit logs, and streaming updates.

text
Control plane:
- Flag authoring API
- Targeting rule validator
- Audit log
- Approval workflow
- Configuration publisher

Data plane:
- CDN or streaming config distribution
- SDK local evaluation
- Exposure event ingestion
- Emergency kill switch
Back to Course