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These 2^N problems are really under appreciated, especially with experiments and feature flags. We ship an app with tens of thousands of flags! And chide each o

These 2^N problems are really under appreciated, especially with experiments and feature flags. We ship an app with tens of thousands of flags! And chide each other for hacky, irresponsible engineering if we ever neglect to multiply the number of configuration states by two when releasing a new change. What percentage of the configuration space is actually tested? Perhaps one in a billion.

vsareto 6y ago
Aren't you supposed to remove feature flag code after it's found to be stable? Some products block paid features with flags and those stay in, of course. Do others get actual dev time to clear that up, or is it just rolled up into any technical debt work?
- deckard1 6y ago
  > Do others get actual dev time to clear that up Depends on how much influence your PM has over your team and whether your team really cares about going back and cleaning it up or would they rather go and do resume-building features instead. I feel like we already know the answer to this. I've often felt that all PMs should be required to take a class on combinatorics before being allowed to add a single new feature flag. Of course, devs spend countless hours unit testing and going through QA and then some marketing dickbag can come along and stuff a random script tag into the website via Google Tag Manager and destroy the performance or even kill the site entirely. Yeah, I'm a little bit cynical these days.
- closeparen 6y ago
  AFAIK there is automated cleanups for flags abandoned in the "off" position but "on" flags are forever, in case the feature ever needs to be turned off in the future. In theory this promotes reliability, but I think it's rarely understood what non-local effects there might be if a given flag is turned off, and the more time goes on, the less we understand it.
- lazyasciiart 6y ago
  Ha. I'm trying to convince people to delete flags that were released in 2015.
travisjungroth 6y ago
If you have tens of thousands of flags, there is no way you are anywhere close to testing 1 in a billion of your states. 300 binary flags gives you more states than there are atoms in the universe.

vsareto 6y ago

Aren't you supposed to remove feature flag code after it's found to be stable? Some products block paid features with flags and those stay in, of course. Do others get actual dev time to clear that up, or is it just rolled up into any technical debt work?

deckard1 6y ago
> Do others get actual dev time to clear that up Depends on how much influence your PM has over your team and whether your team really cares about going back and cleaning it up or would they rather go and do resume-building features instead. I feel like we already know the answer to this. I've often felt that all PMs should be required to take a class on combinatorics before being allowed to add a single new feature flag. Of course, devs spend countless hours unit testing and going through QA and then some marketing dickbag can come along and stuff a random script tag into the website via Google Tag Manager and destroy the performance or even kill the site entirely. Yeah, I'm a little bit cynical these days.
closeparen 6y ago
AFAIK there is automated cleanups for flags abandoned in the "off" position but "on" flags are forever, in case the feature ever needs to be turned off in the future. In theory this promotes reliability, but I think it's rarely understood what non-local effects there might be if a given flag is turned off, and the more time goes on, the less we understand it.
lazyasciiart 6y ago
Ha. I'm trying to convince people to delete flags that were released in 2015.

travisjungroth 6y ago

If you have tens of thousands of flags, there is no way you are anywhere close to testing 1 in a billion of your states. 300 binary flags gives you more states than there are atoms in the universe.