How We Test a Feature Flag Platform: 1,192 Tests Across 13 SDKs

This was originally published on rollgate.io/blog/how-we-test-rollgate . The Testing Problem No One Talks About Building a feature flag platform means building something that sits in the critical path of every request your customers serve. If a flag evaluation returns the wrong result, your customer's checkout page shows the wrong UI. If the SDK crashes, your customer's app crashes. If the SSE connection drops, flags go stale. The testing surface is enormous: 13 SDKs across 7 languages — React,