Software Engineer, Mobile

Company: Sierra
Location: San Francisco
Posted on: April 1, 2026

Job Description:

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, Paris, Madrid, Munich, Singapore, Japan, and Sydney. 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. The role 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. What you’ll do 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/TypeScript 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, GraphQL) or frontend code to unblock features or fine-tune end-to-end flows, working with the broader Product Engineering team. What you’ll bring 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 trying to integrate your work. Product and UX sensitivity. You have a good feel for interaction design and visual quality. You notice details like animation timing, gesture ergonomics, and accessibility, and you’re willing to iterate with design until the experience feels “just right.” This lines up strongly with our value of craftsmanship. High-bandwidth collaboration. You communicate clearly with designers, product managers, and other engineers. You can walk through tradeoffs, explain constraints, and adjust plans quickly as we learn from customers. Strong sense of ownership. You’re comfortable owning big areas end to end, from rough concept through launch and iteration. You’ve thrived in fast-moving environments, can operate with limited structure, and care about shipping meaningful improvements quickly without sacrificing quality. Solid understanding of the broader stack . You don’t need to be a backend specialist, but you understand how APIs, authentication, data models, and performance characteristics impact the mobile experience. Experience with GraphQL and/or Go is a plus. Even better… You’ve built mobile SDKs or framework-style products that other teams integrate into their own applications. You have experience with real-time or media-heavy experiences (messaging, voice, video, or streaming UI). You’ve worked on design systems, component libraries, or shared UI kits across platforms, and know how to balance consistency with platform-native conventions. Our values Trust: We build trust with our customers with our accountability, empathy, quality, and responsiveness. We build trust in AI by making it more accessible, safe, and useful. We build trust with each other by showing up for each other professionally and personally, creating an environment that enables all of us to do our best work. Customer Obsession: We deeply understand our customers’ business goals and relentlessly focus on driving outcomes, not just technical milestones. Everyone at the company knows and spends time with our customers. When our customer is having an issue, we drop everything and fix it. Craftsmanship: We get the details right, from the words on the page to the system architecture. We have good taste. When we notice something isn’t right, we take the time to fix it. We are proud of the products we produce. We continuously self-reflect to continuously self-improve. Intensity: We know we don’t have the luxury of patience. We play to win. We care about our product being the best, and when it isn’t, we fix it. When we fail, we talk about it openly and without blame so we succeed the next time. Family: We know that balance and intensity are compatible, and we model it in our actions and processes. We are the best technology company for parents. We support and respect each other and celebrate each other’s personal and professional achievements. What we offer We want our benefits to reflect our values and offer the following to full-time employees: Flexible (Unlimited) Paid Time Off Medical, Dental, and Vision benefits for you and your family Life Insurance and Disability Benefits Retirement Plan (e.g., 401K, pension) with Sierra match Parental Leave Fertility and family building benefits through Carrot Lunch, as well as delicious snacks and coffee to keep you energized Discretionary Benefit Stipend giving people the ability to spend where it matters most Free alphorn lessons These benefits are further detailed in Sierra's policies, may vary by region, and are subject to change at any time, consistent with the terms of any applicable compensation or benefits plans. Eligible full-time employees can participate in Sierra's equity plans subject to the terms of the applicable plans and policies. Be you, with us We're working to bring the transformative power of AI to every organization in the world. To do so, it is important to us that the diversity of our employees represents the diversity of our customers. We believe that our work and culture are better when we encourage, support, and respect different skills and experiences represented within our team. We encourage you to apply even if your experience doesn't precisely match the job description. We strive to evaluate all applicants consistently without regard to race, color, religion, gender, national origin, age, disability, veteran status, pregnancy, gender expression or identity, sexual orientation, citizenship, or any other legally protected class.

Keywords: Sierra, Milpitas , Software Engineer, Mobile, IT / Software / Systems , San Francisco, California