DublinJS October 2016: Challenges in Scaling a Rapidly Growing App and Team

In this talk we discuss how big apps benefit from strong conventions, how feature flagging makes it easier to release safely and often, and how engaging with the wider open-source community benefits everyone.

Transcript

1. Challenges in Scaling a Rapidly Growing App and Team Lorcan Coyle DublinJS October 2016
2. Big Teams and Big Apps • single code-base for the front-end • many engineers • large surface area • engineer fungibility
3. Big Teams and Big Apps • >50 contributors with >10 commits so far in 2016
4. Strong Conventions • EmberJS is strongly opinionated • happy path (with escape valves) • use patterns library for styling
5. Strong Conventions • important because any part of the app looks much like any other… • any ember app looks much like any other ember app
6. Engineer Fungibility • code looks much the same everywhere in the app • moving teams • changing code • onboarding engineers
7. Feature Flagging • release early, release often • all code ships to master • how do you do a beta programme?
8. Different Features for Different Customers • provide a version specific for the beta customers • provide a mechanism by which beta customers can go down beta code paths
9. Feature Flagging • Provide a features array, which contains the features each customer has access to (should be sparse) • add the feature name to their array to give them access • provided by back-end
10. Feature Flagging • add a computed property to the customer model
11. Feature Flagging • hasRedFeature is now available for branching logic
12. Engaging with Community
13. Ember’s Add-on Ecosystem • addons are modules that can be dropped into an ember app • https://emberobserver.com/
14. Ember’s Add-on Ecosystem • More/better logic in templates: ember-truth-helpers, ember-composable-helpers • Concurrency: ember-concurrency • Model validation: ember-cp-validation • Test mock generation: ember-data-factory-guy
15. We have a problem • Generating urls on a performance-sensitive page is expensive
16. We have a problem • “link-to” is the default way of doing this in ember • must be an quicker way • let’s write a helper (v. fast) • Done.
17. Share the solution • This actually looks useful • Let’s build an ember addon and open-source it • https://github.com/intercom/ember-href-to
18. ember-href-to • In the last year • 30 commits • 16 from seven public contributors • Some fairly significant, e.g., upgrading to support latest version of ember
19. Engaging with Community • Great, but maybe this is so helpful it should just be part of the framework? • let’s write a “request for comment” (RFC) • https://github.com/emberjs/rfcs/pull/92 • …watch this space
20. Thanks Strong Conventions Feature Flagging Engaging with Community @lorcancoyle lorcan@intercom.io