How To Build Feature Flags Like A Senior Dev In 20 Minutes

Feature flags are something you have probably never included in any of your apps, but they are an incredible feature that pretty much every app should include. Most people only think of feature flags as a toggle for new features, but they can be used for A/B testing, kill switches, and so much more. They are relatively easy to implement and provide tons of value.

📚 Materials/References:

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⏱️ Timestamps:

00:00 - Introduction
00:40 - What Are Feature Flags
01:35 - Pros/Cons
06:30 - Simple Code Example
08:20 - Where To Store Feature Flags
12:18 - Advanced Code Example

#FeatureFlags #WDS #CleanCode

[KingInternetEnjoyer]

Literally just got a ticket to add a flag around a new analytics feature yesterday lol your channel speaks to me man 😂 great tips!

[rivershertz]

Kyle - I love love love these deep dives, I find them so valuable!
Thank you so much!

[jaaq]

excactly one of the things i'm implementing for the first time at work atm - cheers mate!

[MohamedAdelQuickDeveloper]

Keep up the brilliant work. 👏Really enjoyed this video and would love to see more about concepts and architectures.

[taksuyu]

Really love the breakdown and would like to see more of these!

[sandrodezerio]

Amazing content Kyle, the concepts that you explain and the importance of them as well, keep doing it please.
thanks for sharing your knowledge !

[TechWithCaleb]

I really like these concept Kyle. Please keep going !

[John-eqcd]

Thanks for providing the github link, it helps understanding a lot to be able to read it through

[futhedude]

Well explanation, especially the database stuff at 8:35, never know we could do that.

[davidentzat]

Thanks for the explanation. I would like, please, more videos about this subject.

[tonyrogers]

GREAT stuff. Please do more like this!

[robertphillips]

Thanks Kyle!

For flexibility, I think using a function for the featureFlagRule would be great. You could just then use arbitrary logic and return a boolean. I'm not sure how nicely this approach would play with database storage though.

[jiayu]

Are you the encyclopedia of web development? 🤩I love this video, thank you for your careful explanation.🥰

[FilipeBento-me]

If you decide to cache it, the TTL needs to be inversely proportional to the request rate and how critical the feature is.

[AnindoSarker]

Really glad to see more advanced content in your channel. I already use feature flags in my office project with the database solution.

VIDEO IDEA: make a video on logging service from simple to advanced

[jfftck]

I find that people start to understand SOLID principles more when using feature flags, as you have to have no side effects with existing code. There is another way to use feature flags, if your app is server side, you can have special headers that you can use when making an HTTP request; for more security, add a special token that only the developers would have.

[vincent_sz]

Great Video. Add unleash to your comparison and everything is green :-D

[jasonennis]

I built a whole system based on this without even knowing what it was, its a tool used to build other website like a temple

[remi-avec-un-i]

I cannot see why using the cache would be a good idea: it will literally break the concept of feature flags, as you will not be able to update them anymore in case of a bug

[cfmanooo]

The main problem with feature toggles is that they usually stay in the code forever and even after some time they got broken by other features. Yes, the clean code, principles, and all. But reality is that in small project, you don't need them, in a big project they eventually get broken... And don't forget that testing is ultimatelly impossible with the amount of all of combinations of turning features on, and off respectively.