Implantation details will depend on your stack, but 3 main things I’d keep in mind: 1. Keep it simple. No elaborate logic. No complex data stores. Just a simpl

Implantation details will depend on your stack, but 3 main things I’d keep in mind: 1. Keep it simple. No elaborate logic. No complex data stores. Just a simple checking of the flag. 2. Do it as close to the source as possible, but have limited trust in your clients - you may have old versions, things not propagating, bugs, etc. So best to have option to degrade both in the client and on the server. If you can do only one, so the server side. 3. Real world test! And test often. Don’t trust test environment. Test on real world traffic. Do periodic tests at small scale (like 0.1% of traffic) but also do more full scale tests on a schedule. If you didn’t test it, it won’t work when you need it. If it worked a year ago, it will likely not work now. If it’s not tested, it’ll likely cause more damage than it’ll solve.