# SDUI at Scale: GraphQL & Elixir at Cars.com with Zack Kayser

Page: https://stenobird.com/podcast/elixir-wizards/sdui-at-scale-graphql-elixir-at-cars-com-with-zack-kayser
Text version: https://stenobird.com/podcast/elixir-wizards/sdui-at-scale-graphql-elixir-at-cars-com-with-zack-kayser.md
Podcast: [Elixir Wizards](https://stenobird.com/podcast/elixir-wizards)
Published: 2025-07-03T10:30:00+00:00
Episode link: https://smartlogic.fireside.fm/s14-e06-sdui-graphql-elixir
Audio file: https://aphid.fireside.fm/d/1437767933/03a50f66-dc5e-4da4-ab6e-31895b6d4c9e/a1f823ee-32ed-47d0-8571-bae12c48ac78.mp3
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JSON: https://stenobird.com/v1/public/podcasts/elixir-wizards/episodes/sdui-at-scale-graphql-elixir-at-cars-com-with-zack-kayser
Duration seconds: 2958

## Resource

Zack Kayser, Staff Software Engineer at cars.com, joins Elixir Wizards Sundi Myint and Charles Suggs to discuss how Cars.com adopted a server-driven UI (SDUI) architecture powered by Elixir and GraphQL to deliver consistent, updatable interfaces across web, iOS, and Android. We explore why SDUI matters for feature velocity, how a mature design system and schema planning make it feasible, and what it takes, culturally and technically, to move UI logic from client code into a unified backend. Key topics discussed in this episode: SDUI fundamentals and how it differs from traditional server-side rendering GraphQL as the single source of truth for UI components and layouts Defining abstract UI components on the server to eliminate duplicate logic Leveraging a robust design system as the foundation for SDUI success API-first development and cross-team coordination for schema changes Mock data strategies for early UI feedback without breaking clients Handling breaking changes and hot-fix deployments via server-side updates Enabling flexible layouts and A/B testing through server-controlled ordering Balancing server-driven vs. client-managed UI Iterative SDUI rollout versus “big-bang” migrations in large codebases Using type specs and Dialyxir for clear cross-team communication Integration testing at the GraphQL layer to catch UI regressions early Quality engineering’s role in validating server-driven interfaces Production rollback strategies across web and native platforms Considerations for greenfield projects adopting SDUI from day one Zack and Ethan's upcoming Instrumenting Elixir Apps book Links mentioned: https://cars.com https://github.com/absinthe-graphql/absinthe Telemetry & Observability for Elixir Apps Ep: https://youtu.be/1V2xEPqqCso https://www.phoenixframewo…

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