Software Engineer, Mobile

About us

• At Sierra, we’re creating a platform to help businesses build better, more human customer experiences with AI. We are primarily an in-person company based in San Francisco, with growing offices in Atlanta, New York, London, France, Singapore, and Japan.

• We are guided by a set of values that are at the core of our actions and define our culture:
  Trust, Customer Obsession, Craftsmanship, Intensity, and Family. These values are the foundation of our work, and we are committed to upholding them in everything we do.

• Our co-founders are Bret Taylor and Clay Bavor. Bret currently serves as Board Chair of OpenAI. Previously, he was co-CEO of Salesforce (which had acquired the company he founded, Quip) and CTO of Facebook. Bret was also one of Google's earliest product managers and co-creator of Google Maps. Before founding Sierra, Clay spent 18 years at Google, where he most recently led Google Labs.
  
  Earlier, he started and led Google’s AR/VR effort, Project Starline, and Google Lens. Before that, Clay led the product and design teams for Google Workspace.

• We’re looking for a Software Engineer focused on iOS and/or Android to own our Experience SDKs — the native building blocks our customers use to embed Sierra’s chat and voice agents into their mobile apps.

• You’ll be the technical lead for how Sierra shows up on mobile: UI surfaces, animations, voice interactions, performance, and deep operating-system integrations. You’ll work closely with design and our web frontend team to make the mobile experience feel as considered and cohesive as our core product.

• Own the mobile Experience SDKs for iOS and Android. Lead the architecture, implementation, and evolution of our native SDKs that embed Sierra chat and voice agents into customer apps. Make them a joy to integrate for other engineers and a delight to use for end users.

• Deepen OS-level integrations and interactions. Push into platform-native capabilities: notifications, background execution, voice and audio routing, app extensions, system share sheets, in-app attachments, deep links, and other operating-system surfaces that make agents feel truly “at home” on each platform.

• Design and ship best-in-class mobile interfaces. Work hand-in-hand with our design team to translate Figma concepts into fluid, responsive mobile experiences. Sweat the details on motion, gesture handling, transitions, and accessibility so the agent feels fast, natural, and trustworthy on every device.

• Create a robust SDK developer experience. Define clear APIs, documentation, and sample apps that make it simple for customer engineering teams to integrate Sierra. Focus on stability, versioning, upgrade paths, and metrics so that our mobile surfaces are as reliable as they are beautiful.

• Collaborate tightly with web frontend and product teams. Partner with our React/Type Script frontend engineers to keep interactions, visual language, and behavior coherent across web and mobile. Work closely with product and PMM to bring new agent features to mobile in a way that feels native to each platform.

• Champion quality, performance, and craftsmanship. Set the bar for mobile engineering quality at Sierra: smooth animations, low latency, resilient offline behavior, and thoughtful error states. Instrument and profile the experience, then iterate to keep it fast and reliable at scale.

• Work across the stack when needed. While your center of gravity will be Swift and/or Kotlin, you’ll occasionally dip into backend services (Go, Graph
  
  QL) or frontend code to unblock features or fine-tune end-to-end flows, working with the broader Product Engineering team.

• Deep mobile engineering expertise. Significant experience (typically 6–10+ years) building high-quality native mobile apps or SDKs on iOS (Swift) and/or Android (Kotlin). You’ve shipped production code used by large numbers of users and have the scars and judgment that come with that.

• Strong SDK and API design instincts. You’ve built or maintained SDKs, libraries, or shared frameworks before. You care about clean API surfaces, versioning, and backward compatibility, and you empathize with external developers…