Hanna Liebl (http://hannaliebl.com/)
Most developers love to build new things, but maintaining existing software is also an important part of our jobs. In the front end world, the question of what to do with software and tools that become outdated seemingly overnight is a particularly pertinent one. This talk focuses on strategies for maintaining and updating web apps--keeping them evergreen--either by deciding to completely rewrite them or, more interestingly, incrementally updating them. It is told through the story of three web applications on healthcare.gov, and how we implemented a redesign and an internal upgrade from AngularJS to React in time for the seventh health plan open enrollment period in 2019. It talks about strategies for how to decide on large technical changes as a team, how to ship continuously throughout a redesign or rebuild, specific strategies for moving from AngularJS to React, and other questions to consider when thinking about how to build but also maintain apps that will exist and be used by millions of people today and years from now.