Software Engineer, Agent Runtime
Sierra· Customer Experience AI· Oct 22, 2026 · 6d ago
San Francisco, CA
In office
Full-time
Principal
$230K–$390K
4+ years exp
Job description
ABOUT US
Sierra is the leading platform for customer-facing AI agents, working with many of the world's biggest brands — including The GAP, Rocket Mortgage, SoFi, Sutter Health, and SoftBank — to transform how they serve customers and grow their businesses. We are primarily an in-person company based in San Francisco, with growing offices across North America, Europe, and Asia.
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 a commitment to balancing Family along the way. 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 linkedin.com and Clay Bavor linkedin.com. 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.
WHAT YOU'LL DO
- Build the core systems that power agents. You’ll work on the Agent SDK — the orchestration engine, runtime, and primitives that define how agents reason, take actions, and interact with users and systems.
- Design the agentic loop. What primitives do we need to build agents that are steerable and verifiable, while still conversational and adaptive? You’ll help define how agents operate in real-world environments.
- Improve retrieval and grounding. You’ll build systems that ensure agents provide accurate, trustworthy responses by effectively retrieving and using knowledge.
- Build evaluation systems. You’ll design frameworks that allow us and our customers to measure and improve agent quality over time.
WHAT YOU'LL BRING
- A passion for being on the frontier of AI products.
- Strong software engineering fundamentals and experience building production systems.
- Motivation and high-agency to drive outcomes in a high-autonomy culture.
- 4+ years hands-on experience building production products and systems.
- Degree in Computer Science or related field, or equivalent professional experience.
EVEN BETTER
- Experience building AI-powered systems or agent frameworks.
- Experience with retrieval, evaluation systems, or LLM-based applications.
- Experience building developer platforms or SDKs.
- Experience with Go and Typescript.
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 dependent on country of employment
- 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.
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Keywords to mirror
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Benefits
Benefits detected in the listing.
Dental
Vision
Paid Time Off
Parental Leave