@saltnburnem

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Thanks CodeMash!

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Chris DeMars

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@saltnburnem

@chrisdemars.net

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Senior Developer Advocate II

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  • International Speaker
  • Love spooky stuff
  • Tattoo collector
  • Competitive Bass Angler
  • Competitive Paintball Player

About Me

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@saltnburnem

The Power of Feature Flags in CSS Development

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It's not that scary

trust me...

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What is A/B testing?

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What is A/B testing?

A/B testing, otherwise known as split testing, is the process of testing two different versions of a web page or product feature against the original, existing version.

- Talia Nassi

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Why?

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⬇️ Answers ⬇️

  • Awesome user experience
  • Increase revenue
  • Data correlation for better business decisions
  • Fine grained control of code exposure

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How?

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Well set up an experiment of course!

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That is what we call a moron.

That is not an experiment.

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First

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First

Gather that data!

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❗️ Baseline before experiment! ❗️

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Scientific Method

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Scientific Method

  1. Ask a question
  2. Do research
  3. Construct a hypothesis
  4. Experiment
  5. Draw conclusion

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Scientific Method

  1. Construct a hypothesis
  2. Experiment

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If we ship this new button, our retention will increase by 20%.

Hypothesis

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Experiment time!

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Control

Treatment

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Feature Flags

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Segment Users

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Control

Treatment

50%

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Flex that UI muscle!

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You can be a CSS dev and use feature flags!

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CSS...like CSS

IYKYK

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// get treatment
  let treatment = client.getTreatment('css_demo');

  // get features to flip based upon CSS classes
  const featureA = document.querySelectorAll('.a');
  const featureB = document.querySelectorAll('.b');

  if (treatment === 'on') {

      featureB.forEach(element => {
          element.classList.add('hide')
      })
  } else if (treatment === 'off') {
      featureA.forEach(element => {
          element.classList.add('hide')
      })
  } else {
      console.error('Error connecting to Split')
      // default rule here
      featureA.forEach(element => {
          element.classList.add('hide')
      })
  }

});

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Demo

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It's a happy cry!

Go Forth and Test in Production!

Chris DeMars

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Resources

https://bit.ly/css-feature-flags

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