I work at a big EDA corporation, and we make good use of feature flags in our product. Typically, any new feature that needs extra testing than usual will be i

I work at a big EDA corporation, and we make good use of feature flags in our product. Typically, any new feature that needs extra testing than usual will be included behind a gate for one or two major releases before being enabled by default. Then, certain customers who work closely with our support staff will be given "access" to the flag (typically, a beta license is needed before the flag can be enabled -- in some cases, the presence of a valid beta license will even enable new features automatically sans flag). This makes it very easy to roll out beta code: since it's included in the release, every customer already has the code, and beta testers just need to be told about a flag and/or given a beta license. We don't ever need to prepare a special beta release or anything like that. There are other cases where feature flags come in handy, too. For example, sometimes our default behavior does not match our competitor's. For many customers, that's totally fine, it either doesn't matter or they just deal with it. Some customers, however, demand that they get the same behavior as the competitor's product for certain functionality. We can implement a feature that toggles a compatibility mode and stick it behind a flag. These are flags that will typically never be enabled by default, but they make some of our customers very happy. For certain strategic reasons, we obviously prefer that customers just get used to our behavior. (Not to mention that, from a purely technical standpoint, our behavior often makes much more sense anyway. But it's sorta like C: Rust might be technically superior, but C is so entrenched that it's not going to get replaced overnight.) I think I came from an opposite boat than you did, because this is the first company I've worked for that made extensive use of feature flags. Rather than assuming it was some bad practice, I was actually delighted by just how convenient they make certain things. And the best part is that they don't seem to really have any drawbacks.