I wrote a post on how to implement a feature flag system and A/B testing in an Elixir app with no need for third-party services or libraries. I used this system in production with a relatively large platform.
I’m also getting into what I think is some pitfalls of A/B testing and what mindset we should have when building products, with this quote in mind:
When a measure becomes a target, it ceases to be a good measure