Summary

Any software project that is worked on or used by multiple people will inevitably reach a point where certain capabilities need to be turned on or off. In this episode Pete Hodgson shares his experience and insight into when, how, and why to use feature flags in your projects as a way to enable that practice. In addition to the simple on and off controls for certain logic paths, feature toggles also allow for more advanced patterns such as canary releases and A/B testing. This episode has something useful for anyone who works on software in any language.

Announcements

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• Your host as usual is Tobias Macey and today I’m interviewing Pete Hodgson about the concept of feature flags and how they can benefit your development workflow

Interview

• Introductions
• How did you get introduced to Python?
• Can you start by describing what a feature flag is?
  • What was your first experience with feature flags and how did it affect your approach to software development?
• What are some of the ways that feature flags are used?
  • What are some antipatterns that you have seen for teams using feature flags?
• What are some of the alternative development practices that teams will employ to achieve the same or similar outcomes to what is possible with feature flags?
• Can you describe some of the different approaches to implementing feature flags in an application?
  • What are some of the common pitfalls or edge cases that teams run into when building an in-house solution?
  • What are some useful considerations when making a build vs. buy decision for a feature toggling service?
• What are some of the complexities that get introduced by feature flags for mantaining application code over the long run?
• What have you found to be useful or effective strategies for cataloging and documenting feature toggles in an application, particularly if they are long lived or for open source applications where there is no institutional context?
• Can you describe some of the lifecycle considerations for feature flags, and how the design, implementation, or use of them changes for short-lived vs long-lived use cases?
• What are some cases where the overhead of implementing and maintaining a feature flag infrastructure outweighs the potential benefit?
• What advice or references do you recommend for anyone who is interested in using feature flags for their own work?

Keep In Touch

• Website
• @ph1 on Twitter
• moredip on GitHub

Picks

• Tobias
  • Circuit Playground Express
    • CircuitPython Episode
• Pete
  • Accelerate by Nicole Forsgren, Jez Humble, and Gene Kim

Closing Announcements

• Thank you for listening! Don’t forget to check out our other show, the Data Engineering Podcast for the latest on modern data management.
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Links

• Perl
• Ruby
• Django
• Feature Flag
• Pete’s Blog Post On Feature Flags
• Thoughtworks
• Continuous Delivery
• Continuous Delivery Book
• Trunk Based Development
• Branch By Abstraction
• Technical Debt
• Strategy Pattern
• Polymorphism

The intro and outro music is from Requiem for a Fish The Freak Fandango Orchestra / CC BY-SA