Platform

The first feature flag I implemented was a boolean in a config file. Toggle it to true, deploy, feature is on. Toggle to false, deploy, feature is off. Simple. The fifteenth feature flag was a percentage rollout with user cohort targeting, metric-based automatic rollback, and a kill-switch that worked without a deployment. The gap between those two implementations is what this post is about. ...

The fintech startup hit the platform question about eighteen months in. We had product-market fit, we were growing, and the engineering team was doubling every six months. The systems that had worked at ten engineers were showing strain at twenty-five. The question became: dedicate engineering time to platform work, or keep all capacity on product features? This is a hard question. The people who get it right aren’t smarter — they’re clearer about what they’re actually trading off. ...