#
msgid ""
msgstr ""

msgid ""
"title: Rollout, feature flag, experiment, operational toggle\n"
"date: 2020-10-19\n"
"layout: slides\n"
"lang: en\n"
"ref: rollout-feature-flag-experiment-operational-toggle"
msgstr ""

msgid "Rollout, feature flag, experiment, operational toggle"
msgstr ""

msgid "Different use cases for **backend**, **frontend** and **mobile**"
msgstr ""

msgid ""
"\"Feature flags\" tend to come up when talking about **continuous "
"deployment**"
msgstr ""

msgid "???"
msgstr ""

msgid "I'm using \"quotes\" because I'm mixing up different meanings of \"rollout\""
msgstr ""

msgid "CI"
msgstr ""

msgid "continuous integration"
msgstr ""

msgid "CD"
msgstr ""

msgid "continuous delivery"
msgstr ""

msgid "**continuous deployment**"
msgstr ""

msgid "Background: build vocabulary, why are feature flags related to CD"
msgstr ""

msgid "CI solves: manual integration of long-lived branches"
msgstr ""

msgid "CD solves: automation of deployment process"
msgstr ""

msgid "CD solves: releases as frequent as possible"
msgstr ""

msgid "That's where the \"GoCD\" name comes from"
msgstr ""

msgid "Types:"
msgstr ""

msgid "rollout"
msgstr ""

msgid "feature flag"
msgstr ""

msgid "experiment"
msgstr ""

msgid "operational toggle"
msgstr ""

msgid "For *rolling out* a new version of software"
msgstr ""

msgid "**Short-lived** using **percentages**"
msgstr ""

msgid ""
"a [new deployment of "
"k8s](https://kubernetes.io/docs/concepts/workloads/controllers/deployment/#creating-"
"a-deployment)"
msgstr ""

msgid ""
"new [APK released to the Play "
"Store](https://support.google.com/googleplay/android-"
"developer/answer/6346149?hl=en)"
msgstr ""

msgid "Relevant as long as the new code is deployed"
msgstr ""

msgid "For turning a feature *on* or *off*"
msgstr ""

msgid ""
"**Medium-lived** using **allow list**, **A/B test**, **percentage**, **app "
"version**, *etc*."
msgstr ""

msgid "`:new-chargeback-flow`"
msgstr ""

msgid "`:new-debit-card-activation-screen`"
msgstr ""

msgid "Relevant as long as the new code is being developed"
msgstr ""

msgid "For analyzing behaviour"
msgstr ""

msgid "**Medium-lived** using **allow list** and **A/B test**"
msgstr ""

msgid "`:debit-withdrawal-test`"
msgstr ""

msgid "For disabling features in `#crash`-like situations"
msgstr ""

msgid "**Long-lived** using **percentage**"
msgstr ""

msgid "`:bank-barcode-payment`"
msgstr ""

msgid "`:savings-bank-barcode-query-provider`"
msgstr ""

msgid "Lives for as long as the code is in production."
msgstr ""

msgid "It feels like a system-level circuit breaker."
msgstr ""

msgid "We now know about the types"
msgstr ""

msgid ""
"But they have different relevance for **backend**, **frontend** and "
"**mobile**"
msgstr ""

msgid "backend"
msgstr ""

msgid "**rollout**: k8s blue/green, canary and `common-rollout`"
msgstr ""

msgid "**feature flag**: `common-rollout` and datasets"
msgstr ""

msgid "**experiment**: `common-xp`"
msgstr ""

msgid "**operational toggle**: `common-rollout`"
msgstr ""

msgid ""
"This is a bit why common-rollout isn't called *common-feature-flag*: it was "
"initially designed with backend usage of mostly *rollouts* in mind, and just"
" a bit *feature flags*."
msgstr ""

msgid ""
"Avoid using configuration for doing operational toggles: it is less dynamic,"
" so it defeats the purpose."
msgstr ""

msgid "frontend"
msgstr ""

msgid "**rollout**: CDN and page refreshes"
msgstr ""

msgid ""
"**feature flag**: percentages and maybe IPs (no `:customer/id` on the "
"website)"
msgstr ""

msgid "**experiment**: via dynamic backend control"
msgstr ""

msgid "**operational toggle**: via dynamic backend control"
msgstr ""

msgid "mobile"
msgstr ""

msgid "**rollout**: app stores"
msgstr ""

msgid "**feature flag**: via dynamic backend control"
msgstr ""

msgid "Key differentiator is"
msgstr ""

msgid "How much **control** we have over the **environment**"
msgstr ""

msgid "**backend**"
msgstr ""

msgid "Full control"
msgstr ""

msgid "🎉"
msgstr ""

msgid "Can edit, update and even delete rollouts as desired."
msgstr ""

msgid "Mix and match at will!"
msgstr ""

msgid "**frontend**"
msgstr ""

msgid "Partial control"
msgstr ""

msgid "When choose when to make a new version available"
msgstr ""

msgid ""
"We can control when a new version is available, partially when someone will "
"upgrade it."
msgstr ""

msgid "But it is easy to fallback to \"reload the page and try again\"."
msgstr ""

msgid "**mobile**"
msgstr ""

msgid "Very limited control"
msgstr ""

msgid "app stores can restrict updates (worse for iOS)"
msgstr ""

msgid "customers still have to download new versions"
msgstr ""

msgid "Costs"
msgstr ""

msgid "more complex code"
msgstr ""

msgid "compatibility with old app versions"
msgstr ""

msgid "nesting is exponential"
msgstr ""

msgid "Benefits"
msgstr ""

msgid "dynamicity"
msgstr ""

msgid "Best practices"
msgstr ""

msgid "Dynamic content > feature flag"
msgstr ""

msgid "Always true for **mobile**, almost always for **frontend**"
msgstr ""

msgid "Use `:include-list` for named groups"
msgstr ""

msgid "Always true for **backend**, **frontend** and **mobile**"
msgstr ""

msgid "{% raw %}"
msgstr ""

msgid ""
"{:rules\n"
" #{{:type    :include-list\n"
"    :content {:filename \"debit-team-members.txt\"}}}}\n"
msgstr ""

msgid "{% endraw %}"
msgstr ""

msgid "Always use `:app-version`"
msgstr ""

msgid "only for **mobile**"
msgstr ""

msgid ""
"{:rules\n"
" #{{:type    :app-version\n"
"    :content {:min-version #{{:platform :android\n"
"                              :code     1000000}\n"
"                             {:platform :ios\n"
"                              :code     2000000}}}}}}\n"
msgstr ""

msgid "Extend `common-rollout` if required"
msgstr ""

msgid "That's how `:include-list`, `:app-version`, *etc.* were born"
msgstr ""

msgid "Beware of many nested feature flags"
msgstr ""

msgid "True for **backend**, **frontend** and **mobile**"
msgstr ""

msgid "Exponential growth of combinations"
msgstr ""

msgid "Don't delete app-facing feature flags"
msgstr ""

msgid "True for **mobile**"
msgstr ""

msgid "This could break old app versions, only do this intentionally"
msgstr ""

msgid ""
"We don't have (yet) a strategy for dealing with LTS of the app, and we just "
"say: \"we'll support every app version out there\"."
msgstr ""

msgid "Include a feature flag on the whiteboarding phase"
msgstr ""

msgid "Include deleting/retiring the feature flag at the end"
msgstr ""

msgid "Avoid renaming a feature flag"
msgstr ""

msgid "Use `:app-version` with `:min-version` instead"
msgstr ""

msgid "And most importantly..."
msgstr ""

msgid "***Always*** rely on a feature flag on the app"
msgstr ""

msgid "Never do a hot fix, avoid expedited releases at all costs"
msgstr ""

msgid ""
"The app is where we have less control, so the feature flag is how we get "
"some of that control back."
msgstr ""

msgid "This doesn't mean you'll need 1 feature flag per PR"
msgstr ""

msgid ""
"There's not such thing as: \"This is such a small thing, it doesn't need a "
"feature flag\""
msgstr ""

msgid ""
"You should ask yourself: \"It this crashes the app, am I OK with waiting for"
" the next release train?\""
msgstr ""

msgid "Thank you!"
msgstr ""

msgid "References:"
msgstr ""

msgid "these slides: [{{ site.tld }}/slides.html]({% link slides.md %})"
msgstr ""

msgid ""
"[prose version of this presentation]({% link _articles/2020-10-19-feature-"
"flags-differences-between-backend-frontend-and-mobile.md %})"
msgstr ""

msgid ""
"\"[Feature Toggles (aka Feature "
"Flags)](https://martinfowler.com/articles/feature-toggles.html)\", by Pete "
"Hodgson"
msgstr ""

msgid ""
"\"[Continuous integration vs. continuous delivery vs. continuous "
"deployment](https://www.atlassian.com/continuous-"
"delivery/principles/continuous-integration-vs-delivery-vs-deployment)\", by "
"Sten Pittet"
msgstr ""

msgid ""
"[Accelerate](https://itrevolution.com/book/accelerate/), by N. Forsgren, J. "
"Humble and G. Kim"
msgstr ""