In a new post to his site Leonid Mamchenkov talks about feature flags, a handy tool you can use in your application to enable/disable features and or risky changes in your code allowing you more production-level control.

Today edition of the “Four short links” from the O’Reilly Radar, brings a quick overview of the different feature flag implementations. It touches on the following: Command-line flags, with the link to gflags, A/B flags, Dynamic flags [which are more difficult] and more complex systems.

I’ve dealt with feature flags before, but never found an elegant way to scale those. [...] These days, something more robust than that is necessary for some of the projects at work. Gladly, there are plenty of available tools to choose from – no need to reinvent the wheel.

He talks about some of the challenges that he had in his own feature flag implementation including naming of the flags and where the flags should be placed. He then links to the PHP Feature Flags site and various PHP libraries that implement feature flags slightly differently and cover cookie-based, IP-based and URL-based features. He ends the post by pointing out that the lack of feature flags in any complex application is usually considered toxic when it comes to being able to scale an application correctly.