Software Engineer, Horizon

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 https://www.linkedin.com/in/brettaylor/ and Clay Bavor https://www.linkedin.com/in/claybavor/. 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 primitives for self improvement: Create the feedback loops, evaluation systems, memory, signals, and decisioning infrastructure that help long-running agents learn from outcomes and improve over time.

- Build the future of long-horizon agents: Design and ship agents that pursue complex business outcomes over days, weeks, or months across voice, SMS, email, and other channels.

- Turn 0-to-1 work into a platform: Identify patterns and build reusable systems, abstractions, and tools that make future Horizon agents faster and easier to launch.

- Solve technically complex problems: Build across orchestration, integrations, data, memory, signals, decisioning, observability, and multi-channel engagement.

- Shape the Horizon product: Surface platform gaps through hands-on implementation and work with product and engineering to define Horizon’s architecture and roadmap.

- Create a clean path beyond the POC: Once a solution is validated, translate what you built into durable product capabilities and enable a successful handoff for continued deployment.

What you’ll bring

- Experience building and scaling end-to-end production systems.

- Strong platform and systems engineering fundamentals.

- The ability to move between customer problems, product design, and technical implementation.

- Strong technical judgment in ambiguous, fast-changing environments.

- A builder’s mindset and the ability to take products from zero to one.

- Comfort working directly with customers and understanding complex business processes.

- High agency, adaptability, and clear communication.

- At least two years of professional software engineering experience

- Experience with Python, TypeScript, or Go and React.

Even better

- Experience as a founder, founding engineer, or early engineer at a startup.

- Experience building workflow, orchestration, event-driven, or distributed systems.

- Experience developing platforms or reusable infrastructure for other engineers.

- Experience building or deploying AI and LLM-powered products.

- Familiarity with enterprise integrations, APIs, data pipelines, and systems of record.

- Experience working in complex industries such as financial services or healthcare.

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 goal …